JavaScript (JS) is a lightweight, interpreted, or just-in-time compiled programming language with first-class functions. While it is most well-known as the scripting language for Web pages, many non-browser environments also use it, such as Node.js, Apache CouchDB and Adobe Acrobat. JavaScript is a prototype-based, multi-paradigm, single-threaded, dynamic language, supporting object-oriented, imperative, and declarative (e.g. functional programming) styles. Read more about JavaScript.
This section is dedicated to the JavaScript language itself, and not the parts that are specific to Web pages or other host environments. For information about API specifics to Web pages, please see Web APIs and DOM.
The standard for JavaScript is ECMAScript. As of 2012, all modern browsers fully support ECMAScript 5.1. Older browsers support at least ECMAScript 3. On June 17, 2015, ECMA International published the sixth major version of ECMAScript, which is officially called ECMAScript 2015, and was initially referred to as ECMAScript 6 or ES6. Since then, ECMAScript standards are on yearly release cycles. This documentation refers to the latest draft version, which is currently ECMAScript 2020.
Do not confuse JavaScript with the Java programming language. Both "Java" and "JavaScript" are trademarks or registered trademarks of Oracle in the U.S. and other countries. However, the two programming languages have very different syntax, semantic, and use.
JavaScript comments can be used to explain JavaScript code, and to make it more readable. JavaScript comments can also be used to prevent execution, when testing alternative code.
Single Line Comments
Single line comments start width / /.
Any text between / / and the end of the line will be ignored by JavaScript (will not be executed).
This example uses a single-line comment before each code line:
Example
// Change heading:
document.getElementById("myH").innerHTML = "My First Page";
// Change paragraph:
document.getElementById("myP").innerHTML = "My first paragraph.";
This example uses a single line comment at the end o f each line to explain the code:
Example
var x = 5; // Declare x, give it the value of 5
var y = x + 2; // Declare y, give it the value of x + 2
Multi-line Comments
Multi-line comments start with /* and end with */.
Any text between /* and */ will be ignored by JavaScript.
This example uses a multi-line comment (a comment block) to explain the code:
Example
/*
The code below will change
the heading with id = "myH"
and the paragraph with id = "myP"
in my web page:
*/
document.getElementbyId("myH").innerHTML = "My First Page";
document.getElementById("myP").innerHTML = "My first paragraph.";
Using Comments to Prevent Execution
Using comments to prevent execution of code is suitable for code testing.
Adding / / in front of a code line changes the code lines from an executable line to a comment.
This example uses // to prevent execution of one of the code lines:
Example
//document.getElementById("myH").innerHTML = "My first page";
document.getElementById("myP").innerHTML = "My firts paragraph.";
This example uses a comment block to prevent execution of multiple line:
/*
document.getElementById("myH").innerHTML = "My First Page";
document.getElementById("myP").innerHTML = "My first paragraph.";
*/
JavaScript variables are containers for storing data values.
In this exampe, x, y, and z, are variables, declared with the var keyword:
Example
var x = 5;
var y = 6;
var z = x + y;
From the example above, you can expect:
- x stores the value 5
- y stores the value 6
- z stores the value 11
Using let and const
Before 2015, using the var keyword was the only way to declare a JavaScript variable.
The 2015 version of JavaScript (ES6 - ECMAScript 2015) allows the use of the const keyword to define a variable that cannot be reassigned, and the let keyword to define a variable with restricted scope.
Because it is a little complicated to describe the difference between these keywords, and because the are not supported in older beowsers, the first part of this tutorial will most often use var.
Much Like Algebra
In this example, price1, price2, and total, are variables:
Example
var price1 = 5;
var price2 = 6;
var total = price1 + price2;
In programming, just like in algebra, we use variables (like price1) to hold values.
In programming, just like in algebra, we use variables in expressions (total = price1 + price2).
From the example above, you can calculate the total to be 11.
JavaScript Identifiers
All JavaScript variables must be identified with unique names.
These unique names are called identifiers.
Identifiers can be short names (like x and y) or more descriptive names (age, sum, totalVolume).
The general rules for constructing names for variables (unique identifiers) are:
- Names can contain letters, digits, underscores, and dollar signs.
- Names must begin with a letter
- Names can also begin with $ and _ (but we will not use it in this tutorial)
- Names are case sensitive (y and Y are different variables)
- Reserved words (like JavaScript keywords) cannot be used as names
The Assignment Operator
In JavaScript, the equal sign (=) is an "assignment" operator, not an "equal to" operator.
This is different from algebra. The following does not make sense in algebra:
x = x + 5
In JavaScript, however, it makes perfect sense: it assigns the value of x + 5 to x.
(It calculates the value of x + 5 and puts the result into x. The value of x is incremented by 5.)
JavaScript Data Types
JavaScript variables can hold numbers like 100 and text values like "John Doe".
In programming, text values are called text strings.
JavaScript can handle many types of data, but for now, just think of numbers and strings.
Strings are written inside double or single quotes. Numbers are written without quotes.
If you put a number in quotes, it will be treated as a text string.
Example
var pi = 3.14;
var person = "John Doe";
var answer = 'Yes I am!';
Declaring (Creating) JavaScript Variables
Creating a variable in JavaScript is called "declaring" a variable.
You declare a JavaScript variable with the var keyword:
var carName;
After the declaration, the variable has no value (technically it has the value of undefined).
To assign a value to the variable, use the equal sign:
carName = "Volvo";
You can also assign a value to the variable when you declare it:
var carName = "Volvo";
In the example below, we create a variable called carName and assign the value "Volvo" to it.
Then we "output" the value inside an HTML paragraph with id="demo":
Example

One Statement, Many Variables
You can declare many variables in one statement.
Start the statement with var and separate the variables by comma:
var person = "John Doe", carName = "Volvo", price = 200;
A declaration can span multiple lines:
var person = "John Doe",
carName = "Volvo",
price = 200;
Value = undefined
In computer programs, variables are often declared without a value. The value can be something that has to be calculated, or something that will be provided later, like user input.
A variable declared without a value will have the value undefined.
The variable carName will have the value undefined after the execution of this statement:
Example
var carName;
Re-Declaring JavaScript Variables
If you re-declare a JavaScript variable, it will not lose its value.
The variable carName will still have the value "Volvo" after the execution of these statements:
Example
var carName = "Volvo";
var carName;
JavaScript Arithmetic
As with algebra, you can do arithmetic with JavaScript variables, using operators like = and +:
Example
var x = 5 + 2 + 3;
You can also add strings, but strings will be concatenated:
Example
var x = "John" + " " + "Doe";
Also try this:
Example
var x = "5" + 2 + 3;
JavaScript Dollar Sign $
Remember that JavaScript identifiers (names) must begin with:
- A letter (A-Z or a-z)
- A dollar sign ($)
- Or an underscore (_)
- Since JavaScript treats a dollar sign as a letter, identifiers containing $ are valid variable names:
Example
var $$$ = "Hello World";
var $ = 2;
var $myMoney = 5;
Using the dollar sign is not very common in JavaScript, but professional programmers often use it as an alias for the main function in a JavaScript library.
In the JavaScript library jQuery, for instance, the main function $ is used to select HTML elements. In jQuery $("p"); means "select all p elements".
JavaScript Underscore (_)
Since JavaScript treats underscore as a letter, identifiers containing _ are valid variable names:
Example
var _lastName = "Johnson";
var _x = 2;
var _100 = 5;
JavaScript variables can hold many data types: numbers, strings, objects and more:
var length = 16; // Number
var lastName = "Johnson"; // String
var x = {firstName:"John", lastName:"Doe"}; // Object
The Concept of Data Types
In programming, data types is an important concept.
To be able to operate on variables, it is important to know something about the type.
Without data types, a computer cannot safely solve this:
var x = 16 + "Volvo";
Does it make any sense to add "Volvo" to sixteen? Will it produce an error or will it produce a result
JavaScript will treat the example above as
var x = "16" + "Volvo";
Example
var x = 16 + "Volvo";
Example
var x = "Volvo" + 16;
JavaScript evaluates expressions from left to right. Different sequences can produce different results:
JavaScript:
var x = 16 + 4 + "Volvo";
Result:
20Volvo
JavaScript:
var x = "Volvo" + 16 + 4;
Result:
Volvo164
In the first example, JavaScript treats 16 and 4 as numbers, until it reaches "Volvo".
In the second example, since the first operand is a string, all operands are treated as strings
JavaScript Types are Dynamic
JavaScript has dynamic types. This means that the same variable can be used to hold different data types:
Example
var x; // Now x is undefined
x = 5; // Now x is a Number
x = "John"; // Now x is a String
JavaScript Strings
A string (or a text string) is a series of characters like "John Doe".
Strings are written with quotes. You can use single or double quotes:
Example
var carName1 = "Volvo XC60"; // Using double quotes
var carName2 = 'Volvo XC60'; // Using single quotes
You can use quotes inside a string, as long as they don't match the quotes surrounding the string:
Example
var answer1 = "It's alright"; // Single quote inside double quotes
var answer2 = "He is called 'Johnny'"; // Single quotes inside double quotes
var answer3 = 'He is called "Johnny"'; // Double quotes inside single quotes
JavaScript Numbers
JavaScript has only one type of numbers.
Numbers can be written with, or without decimals:
Example
var x1 = 34.00; // Written with decimals
var x2 = 34; // Written without decimals
Extra large or extra small numbers can be written with scientific (exponential) notation:
Example
var y = 123e5; // 12300000
var z = 123e-5; // 0.00123
JavaScript Booleans
Booleans can only have two values: true or false.
Example
var x = 5;
var y = 5;
var z = 6;
(x == y) // Returns true
(x == z) // Returns false
Booleans are often used in conditional testing.
JavaScript Arrays
JavaScript arrays are written with square brackets.
Array items are separated by commas.
The following code declares (creates) an array called cars, containing three items (car names):
Example
var cars = ["Saab", "Volvo", "BMW
Array indexes are zero-based, which means the first item is [0], second is [1], and so on.
JavaScript Objects
JavaScript objects are written with curly braces {}.
Object properties are written as name:value pairs, separated by commas.
Example
var person = {firstName:"John", lastName:"Doe", age:50, eyeColor:"blue
The object (person) in the example above has 4 properties: firstName, lastName, age, and eyeColor.
The typeof Operator
You can use the JavaScript typeof operator to find the type of a JavaScript variable.
The typeof operator returns the type of a variable or an expression:
Example
typeof "" // Returns "string"
typeof "John" // Returns "string"
typeof "John Doe" // Returns "string"
Example
typeof 0 // Returns "number"
typeof 314 // Returns "number"
typeof 3.14 // Returns "number"
typeof (3) // Returns "number"
typeof (3 + 4) // Returns "number"
Undefined
In JavaScript, a variable without a value, has the value undefined. The type is also undefined.
Example
var car; // Value is undefined, type is undefined
Any variable can be emptied, by setting the value to undefined. The type will also be undefined.
Example
car = undefined; // Value is undefined, type is undefined
Empty Values
An empty value has nothing to do with undefined.
An empty string has both a legal value and a type.
Example
var car = ""; // The value is "", the typeof is "string"
Null
In JavaScript null is "nothing". It is supposed to be something that doesn't exist.
Unfortunately, in JavaScript, the data type of null is an object.
You can consider it a bug in JavaScript that typeof null is an object. It should be null.
You can empty an object by setting it to null:
Example
var person = {firstName:"John", lastName:"Doe", age:50, eyeColor:"blue"};
person = null; // Now value is null, but type is still an object
You can also empty an object by setting it to undefined:
Example
var person = {firstName:"John", lastName:"Doe", age:50, eyeColor:"blue"};
person = undefined; // Now both value and type is undefined
Difference Between Undefined and Null
undefined and null are equal in value but different in type:
typeof undefined // undefined
typeof null // object
null === undefined // false
null == undefined // true
Primitive Data
A primitive data value is a single simple data value with no additional properties and methods.
The typeof operator can return one of these primitive types:
- string
- number
- boolean
- undefined
Example
typeof "John" // Returns "string"
typeof 3.14 // Returns "number"
typeof true // Returns "boolean"
typeof false // Returns "boolean"
typeof x // Returns "undefined" (if x has no value)
Complex Data
The typeof operator can return one of two complex types:
- function
- object
The typeof operator returns "object" for objects, arrays, and null.
The typeof operator does not return "object" for functions.
Example
typeof {name:'John', age:34} // Returns "object"
typeof [1,2,3,4] // Returns "object" (not "array", see note below)
typeof null // Returns "object"
typeof function myFunc(){} // Returns "function"
Example
Assign values to variables and add them together:
var x = 5; // assign the value 5 to x
var y = 2; // assign the value 2 to y
var z = x + y; // assign the value 7 to z (5 + 2)
The assignment operator (=) assigns a value to a variable.
Assignment
var x = 10;
The addition operator (+) adds numbers:
Adding
var x = 5;
var y = 2;
var z = x + y;
The multiplication operator (*) multiplies numbers.
Multiplying
var x = 5;
var y = 2;
var z = x * y;
JavaScript Arithmetic Operators
Arithmetic operators are used to perform arithmetic on numbers:
| Operator | Description |
|---|---|
| + | Addition |
| - | Subtraction |
| * | Multiplicaction |
| ** | Exponetiation(ES2016) |
| / | Division |
| % | Modulus(Division Remainder) |
| ++ | Increment |
| -- | Decrement |
JavaScript Assignment Operators
Assignment operators assign values to JavaScript variables.
| Operator | Example | Same As |
|---|---|---|
| = | x = y | x = y |
| += | x += y | x = x + y |
| -= | x -= y | x = x - y |
| *= | x *= y | x = x * y |
| /= | x /= y | x = x / y |
| %= | x %= y | x = x % y |
| **= | x **= y | x = x ** y |
The addition assignment operator (+=) adds a value to a variable.
Assignment
var x = 10;
x += 5;
JavaScript String Operators
The + operator can also be used to add (concatenate) strings.
Example
var txt1 = "John";
var txt2 = "Doe";
var txt3 = txt1 + " " + txt2;
The result of txt3 will be:
John Doe
The += assignment operator can also be used to add (concatenate) strings:
Example
var txt1 = "What a very ";
txt1 += "nice day";
The result of txt1 will be:
What a very nice day
Adding Strings and Numbers
Adding two numbers, will return the sum, but adding a number and a string will return a string:
Example
var x = 5 + 5;
var y = "5" + 5;
var z = "Hello" + 5;
The result of x, y, and z will be:
10
55
Hello5
JavaScript Comparison Operators
| Operator | Description |
|---|---|
| == | eqal to |
| === | equal value and equal type |
| != | not equal |
| !== | not equal value or not equal type |
| > | greater than |
| < | less than |
| >= | greater than or equal to |
| <= | less than or equal to |
| ? | ternary operator |
JavaScript Logical Operators
| Operator | Description |
|---|---|
| && | logical and |
| || | logial or |
| ! | logical not |
JavaScript Type Operators
| Operator | Description |
|---|---|
| instanceof | Returns true if an object is an instance of an object type |
| typeof | Returns the type of a variable |
JavaScript Bitwise Operators
Bit operators work on 32 bits numbers.
Any numeric operand in the operation is converted into a 32 bit number. The result is converted back to a JavaScript number.
| Operator | Description | Example | Same as | Result | Decimal |
|---|---|---|---|---|---|
| & | AND | 5 & 1 | 0101 & 0001 | 0001 | 1 |
| | | OR | 5 | 1 | 0101 || 0001 | 0101 | 5 |
| ~ | NOT | ~ 5 | ~0101 | 1010 | 10 |
| ^ | XOR | 5 ^ 1 | 0101 ^ 0001 | 0100 | 4 |
| << | Zero fill left shift | 5 << 1 | 0101 << 1 | 1010 | 10 |
| >> | Signed right sift | 5 >> 1 | 0101 >> 1 | 0010 | 2 |
| >>> | Zero fill right shift | 5 >>> 1 | 0101 >>> 1 | 0010 | 2 |
What is the DOM
The Document Object Model (DOM) is a programming interface for HTML and XML documents. It represents the page so that programs can change the document structure, style, and content. The DOM represents the document as nodes and objects. That way, programming languages can connect to the page.
A Web page is a document. This document can be either displayed in the browser window or as the HTML source. But it is the same document in both cases. The Document Object Model (DOM) represents that same document so it can be manipulated. The DOM is an object-oriented representation of the web page, which can be modified with a scripting language such as JavaScript.
For example, the standard DOM specifies that the querySelectorAll method in the code below must return a list of all the
elements in the document:
const paragraphs = document.querySelectorAll("p");
// paragraphs[0] is the first element
// paragraphs[1] is the second
element, etc.
alert(paragraphs[0].nodeName);
All of the properties, methods, and events available for manipulating and creating web pages are organized into objects (for example, the document object that represents the document itself, the table object that implements the special HTMLTableElement DOM interface for accessing HTML tables, and so forth). This documentation provides an object-by-object reference to the DOM.
The modern DOM is built using multiple APIs that work together. The core DOM defines the objects that fundamentally describe a document and the objects within it. This is expanded upon as needed by other APIs that add new features and capabilities to the DOM. For example, the HTML DOM API adds support for representing HTML documents to the core DOM.
DOM and JavaScript
The short example above, like nearly all of the examples in this reference, is JavaScript. That is to say, it's written in JavaScript, but it uses the DOM to access the document and its elements. The DOM is not a programming language, but without it, the JavaScript language wouldn't have any model or notion of web pages, HTML documents, XML documents, and their component parts (e.g. elements). Every element in a document—the document as a whole, the head, tables within the document, table headers, text within the table cells—is part of the document object model for that document, so they can all be accessed and manipulated using the DOM and a scripting language like JavaScript.
In the beginning, JavaScript and the DOM were tightly intertwined, but eventually, they evolved into separate entities. The page content is stored in the DOM and may be accessed and manipulated via JavaScript, so that we may write this approximative equation:
API = DOM + JavaScript
The DOM was designed to be independent of any particular programming language, making the structural representation of the document available from a single, consistent API. Though we focus exclusively on JavaScript in this reference documentation, implementations of the DOM can be built for any language, as this Python example demonstrates:
# Python DOM example
import xml.dom.minidom as m
doc = m.parse(r"C:\Projects\Py\chap1.xml")
doc.nodeName # DOM property of document object
p_list = doc.getElementsByTagName("para")
Accessing the DOM
You don't have to do anything special to begin using the DOM. Different browsers have different implementations of the DOM, and these implementations exhibit varying degrees of conformance to the actual DOM standard (a subject we try to avoid in this documentation), but every web browser uses some document object model to make web pages accessible via JavaScript.
When you create a script–whether it's inline in a

DOM Interfaces
This guide is about the objects and the actual things you can use to manipulate the DOM hierarchy. There are many points where understanding how these work can be confusing. For example, the object representing the HTML form element gets its name property from the HTMLFormElement interface but its className property from the HTMLElement interface. In both cases, the property you want is in that form object.
But the relationship between objects and the interfaces that they implement in the DOM can be confusing, and so this section attempts to say a little something about the actual interfaces in the DOM specification and how they are made available.
Interfaces and Objects
Many objects borrow from several different interfaces. The table object, for example, implements a specialized HTMLTableElement interface, which includes such methods as createCaption and insertRow. But since it's also an HTML element, table implements the Element interface described in the DOM Element Reference chapter. And finally, since an HTML element is also, as far as the DOM is concerned, a node in the tree of nodes that make up the object model for an HTML or XML page, the table object also implements the more basic Node interface, from which Element derives.
When you get a reference to a table object, as in the following example, you routinely use all three of these interfaces interchangeably on the object, perhaps without knowing it.
const table = document.getElementById("table");
const tableAttrs = table.attributes; // Node/Element interface
for (let i = 0; i < tableAttrs.length; i++) {
// HTMLTableElement interface: border attribute
if(tableAttrs[i].nodeName.toLowerCase() == "border")
table.border = "1";
}
// HTMLTableElement interface: summary attribute
table.summary = "note: increased border";
Core Interfaces in the DOM
This section lists some of the most commonly-used interfaces in the DOM. The idea is not to describe what these APIs do here but to give you an idea of the sorts of methods and properties you will see very often as you use the DOM. These common APIs are used in the longer examples in the DOM Examples chapter at the end of this book.
The document and window objects are the objects whose interfaces you generally use most often in DOM programming. In simple terms, the window object represents something like the browser, and the document object is the root of the document itself. Element inherits from the generic Node interface, and together these two interfaces provide many of the methods and properties you use on individual elements. These elements may also have specific interfaces for dealing with the kind of data those elements hold, as in the table object example in the previous section.
The following is a brief list of common APIs in web and XML page scripting using the DOM.
- document.querySelector(selector)
- document.querySelectorAll(name)
- document.createElement(name)
- parentNode.appendChild(node)
- element.innerHTML
- element.style.left
- element.setAttribute()
- element.getAttribute()
- element.addEventListener()
- window.content
- GlobalEventHandlers/onload
- window.scrollTo()
Reacting to Events
A JavaScript can be executed when an event occurs, like when a user clicks on an HTML element.
To execute code when a user clicks on an element, add JavaScript code to an HTML event attribute:
onclick=JavaScript
Examples of HTML events:
- When a user clicks the mouse
- When a web page has loaded
- When an image has been loaded
- When the mouse moves over an element
- When an input field is changed
- When an HTML form is submitted
- When a user strokes a key
In this example, the content of the
 elements is changed when a user clicks on it:
Example
<!DOCTYPE html>

Click on this text!

In this example, a function is called from the event handler:
Example
<!DOCTYPE html>

Click on this text!

HTML Event Attributes
To assign events to HTML elements you can use event attributes.
Example
Assign an onclick event to a button element:
<button onclick="displayDate()">Try it</button>
In the example above, a function named displayDate will be executed when the button is clicked.
Assign Events Using the HTML DOM
The HTML DOM allows you to assign events to HTML elements using JavaScript:
Example
Assign an onclick event to a button element:

In the example above, a function named displayDate is assigned to an HTML element with the id="myBtn".
The function will be executed when the button is clicked.
The onload and onunload Events
The onload and onunload events are triggered when the user enters or leaves the page.
The onload event can be used to check the visitor's browser type and browser version, and load the proper version of the web page based on the information.
The onload and onunload events can be used to deal with cookies.
Example

The onchange Event
The onchange event is often used in combination with validation of input fields.
Below is an example of how to use the onchange. The upperCase() function will be called when a user changes the content of an input field.
Example
<input type="text" id="fname" onchange="upperCase()">
Vire more about DOM Events
Conditional Statements
Very often when you write code, you want to perform different actions for different decisions. You can use conditional statements in your code to do this. In JavaScript we have the following conditional statements:
- Use if to specify a block of code to be executed, if a specified condition is true
- Use else to specify a block of code to be executed, if the same condition is false
- Use else if to specify a new condition to test, if the first condition is false
- Use switch to specify many alternative blocks of code to be executed
The if Statement
Use the if statement to specify a block of JavaScript code to be executed if a condition is true.
Syntax
if (condition) {
// block of code to be executed if the condition is true
}
Example
Make a "Good day" greeting if the hour is less than 18:00:
if (hour < 18) {
greeting = "Good day";
}
The else Statement
Use the else statement to specify a block of code to be executed if the condition is false.
if (condition) {
// block of code to be executed if the condition is true
} else {
// block of code to be executed if the condition is false
}
Example
If the hour is less than 18, create a "Good day" greeting, otherwise "Good evening":
if (hour < 18) {
greeting = "Good day";
} else {
greeting = "Good evening";
}
The else if Statement
Use the else if statement to specify a new condition if the first condition is false.
Syntax
if (condition1) {
// block of code to be executed if condition1 is true
} else if (condition2) {
// block of code to be executed if the condition1 is false and condition2 is true
} else {
// block of code to be executed if the condition1 is false and condition2 is false
}
Example
If time is less than 10:00, create a "Good morning" greeting, if not, but time is less than 20:00, create a "Good day" greeting, otherwise a "Good evening":
if (time < 10) {
greeting = "Good morning";
} else if (time < 20) {
greeting = "Good day";
} else {
greeting = "Good evening";
}
The JavaScript Switch Statement
Use the switch statement to select one of many code blocks to be executed.
Syntax
switch(expression) {
case x:
// code block
break;
case y:
// code block
break;
default:
// code block
}
This is how it works:
- The switch expression is evaluated once.
- The value of the expression is compared with the values of each case.
- If there is a match, the associated block of code is executed.
- If there is no match, the default code block is executed.
Example
The getDay() method returns the weekday as a number between 0 and 6.
(Sunday=0, Monday=1, Tuesday=2 ..)
This example uses the weekday number to calculate the weekday name:
switch (new Date().getDay()) {
case 0:
day = "Sunday";
break;
case 1:
day = "Monday";
break;
case 2:
day = "Tuesday";
break;
case 3:
day = "Wednesday";
break;
case 4:
day = "Thursday";
break;
case 5:
day = "Friday";
break;
case 6:
day = "Saturday";
}
The break Keyword
When JavaScript reaches a break keyword, it breaks out of the switch block.This will stop the execution of inside the block.It is not necessary to break the last case in a switch block. The block breaks (ends) there anyway.
The default Keyword
The default keyword specifies the code to run if there is no case match:
Example
The getDay() method returns the weekday as a number between 0 and 6.
If today is neither Saturday (6) nor Sunday (0), write a default message:
switch (new Date().getDay()) {
case 6:
text = "Today is Saturday";
break;
case 0:
text = "Today is Sunday";
break;
default:
text = "Looking forward to the Weekend";
}
The default case does not have to be the last case in a switch block:
Example
switch (new Date().getDay()) {
default:
text = "Looking forward to the Weekend";
break;
case 6:
text = "Today is Saturday";
break;
case 0:
text = "Today is Sunday";
}
Common Code Blocks
Sometimes you will want different switch cases to use the same code.In this example case 4 and 5 share the same code block, and 0 and 6 share another code block:
Example
switch (new Date().getDay()) {
case 4:
case 5:
text = "Soon it is Weekend";
break;
case 0:
case 6:
text = "It is Weekend";
break;
default:
text = "Looking forward to the Weekend";
}
Switching Details
If multiple cases matches a case value, the first case is selected. If no matching cases are found, the program continues to the default label. If no default label is found, the program continues to the statement(s) after the switch.
Strict Comparison
Switch cases use strict comparison (===). The values must be of the same type to match. A strict comparison can only be true if the operands are of the same type. In this example there will be no match for x:
Example
var x = "0";
switch (x) {
case 0:
text = "Off";
break;
case 1:
text = "On";
break;
default:
text = "No value found";
}
Loops are handy, if you want to run the same code over and over again, each time with a different value. Often this is the case when working with arrays:
Instead of writing:
text += cars[0] + "
";
text += cars[1] + "
";
text += cars[2] + "
";
text += cars[3] + "
";
text += cars[4] + "
";
text += cars[5] + "
";
You can write:
var i;
for (i = 0; i < cars.length; i++) {
text += cars[i] + "
";
}
Different Kinds of Loops
JavaScript supports different kinds of loops:
- for - loops through a block of code a number of times
- for/in - loops through the properties of an object
- for/of - loops through the values of an iterable object
- while - loops through a block of code while a specified condition is true
- do/while - also loops through a block of code while a specified condition is true
The For Loop
The for loop has the following syntax:
for (statement 1; statement 2; statement 3) {
// code block to be executed
}
Statement 1 is executed (one time) before the execution of the code block.
Statement 2 defines the condition for executing the code block.
Statement 3 is executed (every time) after the code block has been executed.
Example
for (i = 0; i < 5; i++) {
text += "The number is " + i + "
";
}
From the example above, you can read:
Statement 1 sets a variable before the loop starts (var i = 0).
Statement 2 defines the condition for the loop to run (i must be less than 5).
Statement 3 increases a value (i++) each time the code block in the loop has been executed.
Statement 1
Normally you will use statement 1 to initialize the variable used in the loop (i = 0).
This is not always the case, JavaScript doesn't care. Statement 1 is optional.
You can initiate many values in statement 1 (separated by comma):
Example
for (i = 0, len = cars.length, text = ""; i < len; i++) {
text += cars[i] + "
";
}
And you can omit statement 1 (like when your values are set before the loop starts):
Example
var i = 2;
var len = cars.length;
var text = "";
for (; i < len; i++) {
text += cars[i] + "
";
}
Statement 2
Often statement 2 is used to evaluate the condition of the initial variable.
This is not always the case, JavaScript doesn't care. Statement 2 is also optional.
If statement 2 returns true, the loop will start over again, if it returns false, the loop will end.
If you omit statement 2, you must provide a break inside the loop. Otherwise the loop will never end. This will crash your browser. Read about breaks in a later chapter of this tutorial.
Statement 3
Often statement 3 increments the value of the initial variable.
This is not always the case, JavaScript doesn't care, and statement 3 is optional.
Statement 3 can do anything like negative increment (i--), positive increment (i = i + 15), or anything else.
Statement 3 can also be omitted (like when you increment your values inside the loop):
Example
var i = 0;
var len = cars.length;
for (; i < len; ) {
text += cars[i] + "
";
i++;
}
The For/In Loop
The JavaScript for/in statement loops through the properties of an object:
Example
var person = {fname:"John", lname:"Doe", age:25};
var text = "";
var x;
for (x in person) {
text += person[x];
}
The For/Of Loop
The JavaScript for/of statement loops through the values of an iterable objects.
for/of lets you loop over data structures that are iterable such as Arrays, Strings, Maps, NodeLists, and more.
The for/of loop has the following syntax:
for (variable of iterable) {
// code block to be executed
}
variable - For every iteration the value of the next property is assigned to the variable. Variable can be declared with const, let, or var.
iterable - An object that has iterable properties.
Looping over an Array
Example
var cars = ["BMW", "Volvo", "Mini"];
var x;
for (x of cars) {
document.write(x + "
");
}
Looping over a String
Example
var txt = "JavaScript";
var x;
for (x of txt) {
document.write(x + "
");
}
The While Loop
The while loop loops through a block of code as long as a specified condition is true.
Syntax
while (condition) {
// code block to be executed
}
Example
In the following example, the code in the loop will run, over and over again, as long as a variable (i) is less than 10:
Example
while (i < 10) {
text += "The number is " + i;
i++;
}
The Do/While Loop
The do/while loop is a variant of the while loop. This loop will execute the code block once, before checking if the condition is true, then it will repeat the loop as long as the condition is true.
Syntax
do {
// code block to be executed
}
while (condition);
Example
The example below uses a do/while loop. The loop will always be executed at least once, even if the condition is false, because the code block is executed before the condition is tested:
Example
do {
text += "The number is " + i;
i++;
}
while (i < 10);
Comparing For and While
If you have read the previous chapter, about the for loop, you will discover that a while loop is much the same as a for loop, with statement 1 and statement 3 omitted.
The loop in this example uses a for loop to collect the car names from the cars array:
Example
var cars = ["BMW", "Volvo", "Saab", "Ford"];
var i = 0;
var text = "";
for (;cars[i];) {
text += cars[i] + "
";
i++;
}
The loop in this example uses a while loop to collect the car names from the cars array:
Example
var cars = ["BMW", "Volvo", "Saab", "Ford"];
var i = 0;
var text = "";
while (cars[i]) {
text += cars[i] + "
";
i++;
}
JavaScript arrays are used to store multiple values in a single variable.
Example
var cars = ["Saab", "Volvo", "BMW"];
What is an Array?
An array is a special variable, which can hold more than one value at a time. If you have a list of items (a list of car names, for example), storing the cars in single variables could look like this:
var car1 = "Saab";
var car2 = "Volvo";
var car3 = "BMW";
However, what if you want to loop through the cars and find a specific one? And what if you had not 3 cars, but 300? The solution is an array! An array can hold many values under a single name, and you can access the values by referring to an index number.
Creating an Array
Using an array literal is the easiest way to create a JavaScript Array.
Syntax:
var array_name = [item1, item2, ...];
Example
var cars = ["Saab", "Volvo", "BMW"];
Spaces and line breaks are not important. A declaration can span multiple lines:
Example
var cars = [
"Saab",
"Volvo",
"BMW"
];
Using the JavaScript Keyword new
The following example also creates an Array, and assigns values to it:
Example
var cars = new Array("Saab", "Volvo", "BMW");
Access the Elements of an Array
You access an array element by referring to the index number. This statement accesses the value of the first element in cars:
var name = cars[0];
Example
var cars = ["Saab", "Volvo", "BMW"];
document.getElementById("demo").innerHTML = cars[0];
Changing an Array Element
This statement changes the value of the first element in cars:
cars[0] = "Opel";
Example
var cars = ["Saab", "Volvo", "BMW"];
cars[0] = "Opel";
document.getElementById("demo").innerHTML = cars[0];
Access the Full Array
With JavaScript, the full array can be accessed by referring to the array name:
Example
var cars = ["Saab", "Volvo", "BMW"];
document.getElementById("demo").innerHTML = cars;
Arrays are Objects
Arrays are a special type of objects. The typeof operator in JavaScript returns "object" for arrays. But, JavaScript arrays are best described as arrays. Arrays use numbers to access its "elements". In this example, person[0] returns John:
Array:
var person = ["John", "Doe", 46];
Objects use names to access its "members". In this example, person.firstName returns John:
Object:
var person = {firstName:"John", lastName:"Doe", age:46};
Array Elements Can Be Objects
JavaScript variables can be objects. Arrays are special kinds of objects. Because of this, you can have variables of different types in the same Array. You can have objects in an Array. You can have functions in an Array. You can have arrays in an Array:
myArray[0] = Date.now;
myArray[1] = myFunction;
myArray[2] = myCars;
Array Properties and Methods
The real strength of JavaScript arrays are the built-in array properties and methods:
Examples
var x = cars.length; // The length property returns the number of elements
var y = cars.sort(); // The sort() method sorts arrays
Array methods are covered in the next chapters.
The length Property
The length property of an array returns the length of an array (the number of array elements).
Example
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.length; // the length of fruits is 4
Accessing the First Array Element
Example
fruits = ["Banana", "Orange", "Apple", "Mango"];
var first = fruits[0];
Accessing the Last Array Element
Example
fruits = ["Banana", "Orange", "Apple", "Mango"];
var last = fruits[fruits.length - 1];
A JavaScript function is a block of code designed to perform a particular task.
A JavaScript function is executed when "something" invokes it (calls it).
Example
function myFunction(p1, p2) {
return p1 * p2; // The function returns the product of p1 and p2
}
JavaScript Function Syntax
A JavaScript function is defined with the function keyword, followed by a name, followed by parentheses ().
Function names can contain letters, digits, underscores, and dollar signs (same rules as variables).
The parentheses may include parameter names separated by commas:
(parameter1, parameter2,The code to be executed, by the function, is placed inside curly brackets: {}
function name(parameter1, parameter2, parameter3) {
// code to be executed
}
Function parameters are listed inside the parentheses () in the function definition. Function arguments are the values received by the function when it is invoked. Inside the function, the arguments (the parameters) behave as local variables.
Function Invocation
The code inside the function will execute when "something" invokes (calls) the function:
- When an event occurs (when a user clicks a button)
- When it is invoked (called) from JavaScript code
- Automatically (self invoked)
You will learn a lot more about function invocation later in this tutorial.
Function Return
When JavaScript reaches a return statement, the function will stop executing. If the function was invoked from a statement, JavaScript will "return" to execute the code after the invoking statement. Functions often compute a return value. The return value is "returned" back to the "caller":
Example
Calculate the product of two numbers, and return the result:
var x = myFunction(4, 3); // Function is called, return value will end up in x
function myFunction(a, b) {
return a * b; // Function returns the product of a and b
}
The result in x will be:
12
Why Functions?
You can reuse code: Define the code once, and use it many times. You can use the same code many times with different arguments, to produce different results.
Example
Convert Fahrenheit to Celsius:
function toCelsius(fahrenheit) {
return (5/9) * (fahrenheit-32);
}
document.getElementById("demo").innerHTML = toCelsius(77);
The () Operator Invokes the Function
Using the example above, toCelsius refers to the function object, and toCelsius() refers to the function result. Accessing a function without () will return the function object instead of the function result.
Example
function toCelsius(fahrenheit) {
return (5/9) * (fahrenheit-32);
}
document.getElementById("demo").innerHTML = toCelsius;
Functions Used as Variable Values
Functions can be used the same way as you use variables, in all types of formulas, assignments, and calculations.
Example
Instead of using a variable to store the return value of a function:
var x = toCelsius(77);
var text = "The temperature is " + x + " Celsius";
You can use the function directly, as a variable value:
var text = "The temperature is " + toCelsius(77) + " Celsius";
Local Variables
Variables declared within a JavaScript function, become LOCAL to the function.Local variables can only be accessed from within the function.
Examgrid-template-columns:ple
// code here can NOT use carName
function myFunction() {
var carName = "Volvo";
// code here CAN use carName
}
// code here can NOT use carName


{{ getPassphraseError() }}
Etched uses a passphrase to protect your data. A sequence of random words (e.g. correct horse battery staple) is a good idea. The longer the password the better. It must be a minimum of {{ PASSPHRASE_MIN_LENGTH }} characters.
Passphrase doesn't match


Every element has an invisible box around it. You can make them visible by defining a border and padding. You can move them around on the page by specifying margins.
First of all, blocks vs. inline: block elements take up the full width of space available and start on a new line, while inline elements only happen within the line. So < h1> is a block element but < a> is an inline element.
When you're making a CSS stylesheet, the syntax goes:
element {
property: value;
property: value;
}
Please don't forget your semicolons. Someday, when you have time to edit the photo, this is going to have a background image. To stick that in and keep it fixed on the page, you're going to do
body {
background-image: url;
background-repeat: no-repeat;
background-position: fixed;
}
You were confused about em. 1em is equal to the current font size, in pixels. So if the font size is 16px, 1em = 16px. If you change the font size, you change em, so be careful. W3schools suggests changing the font-size to 100% and then just operating in em so probably do that.
To format links:
a:link - a normal, unvisited link
a:visited - a link the user has visited
a:hover - a link when the user mouses over it
a:active - a link the moment it is clicked
you can remove the underline by setting text-decoration to "none"
Border styles
dotted - Defines a dotted border
dashed - Defines a dashed border
solid - Defines a solid border
double - Defines a double border
groove - Defines a 3D grooved border. The effect depends on the border-color value
ridge - Defines a 3D ridged border. The effect depends on the border-color value
inset - Defines a 3D inset border. The effect depends on the border-color value
outset - Defines a 3D outset border. The effect depends on the border-color value
none - Defines no border
hidden - Defines a hidden border
This should look better than the other pages now.


subject = "Newsletter subscription"
layout = "FlyNex-Newsletter-Confirmation-Email"
==
Welcome, {{ user }}.
Thanks for your interest in our newsletter at {{ url_protocol_less|capitalize }}!
To complete your subscription please click here:
Link
If you cannot click the link, simply copy and paste the entire link in your browser.
If it weren't you who started this subscription, simply do nothing.


5.5 Running Squid as a Daemon Process
Normally you'll want to run Squid as a daemon process
(i.e., not attached to your terminal window). The easiest way to do
this is simply execute Squid as follows:
% squid -s
The -s option causes Squid to write important status
and warning messages to syslogd. Squid uses the
LOCAL4 facility and the
LOG_WARNING and LOG_NOTICE
priorities. Your syslog daemon may or may not actually log
Squid's messages, depending on how it is configured.
These same messages are written to the cache.log
file, so it is safe to omit the -s option if you
prefer.
When you start Squid without the -N option (as shown
earlier), Squid automatically backgrounds itself and creates a
parent/child process pair. The child process is the one that does all
the real work. The parent process makes sure that a child process is
always running. Thus, if the child process dies unexpectedly, the
parent starts another so that Squid remains in operation. You can see
this parent/child process interaction by looking at your syslog
messages:
Jul 31 14:58:35 zapp squid[294]: Squid Parent: child process 296 started
Here you can see that the parent is process ID 294, and the child is
296. When you look at ps output,
you'll see that the child process is listed as
(squid):
% ps ax | grep squid
294 ?? Is 0:00.01 squid -sD
296 ?? S 0:00.27 (squid) -sD (squid)
If the child Squid process dies unexpectedly, the parent starts
another. For example:
Jul 31 15:02:53 zapp squid[294]: Squid Parent: child process 296 exited due to signal 6
Jul 31 15:02:56 zapp squid[294]: Squid Parent: child process 359 started
In some situations, the child Squid process may die immediately.
Rather than constantly spawning new Squid processes, the parent
process gives up if the child processes won't stay
running for at least 10 seconds five times in a row:
Jul 31 15:13:48 zapp squid[455]: Squid Parent: child process 474 exited with status 1
Jul 31 15:13:48 zapp squid[455]: Exiting due to repeated, frequent failures
If this happens to you, check syslog and Squid's
cache.log for error messages.
5.5.1 The squid_start Script
When Squid runs as a daemon process, it looks for a file named
squid_start in the same directory as the
squid binary. If found, this program is executed
before the parent process forks to run the child process. You can use
this script for certain administrative tasks, such as notifying
someone that Squid is starting, managing log files, etc. Squid
doesn't start the child process until the
squid_start program exits.
|
The squid_start script only works when you start
Squid by its absolute or relative pathname. In other words, Squid
doesn't use the PATH environment
variable to locate squid_start. Thus, you may
want to develop the habit of starting Squid like this:
% /usr/local/squid/sbin/squid -sD
rather than starting Squid like this:
% squid -sD
|
|
|


UIStackView leverages the power of Auto Layout by managing the layout of all the views inside. You can change property of UIStackView or its arranged subview, and place these changes inside an animation block.
For example, changing hidden
property of the arranged subview.
UIView.animateWithDuration(0.3){
viewInsideStackView.hidden = true //or false
}
Here’s the animation.
iOS encourages you to create adaptive UI, when working with UIStackView, you can define size-class specific values for many of the stack view’s properties directly in Interface Builder. UIStackView automatically animates these changes for you.
For example, changing axis
property of UIStackView in CompactHeight, and with some tweaks of the arranged subview’s constraints. You can have this animation without coding.
For the detail of how constraints are set up, see the full project at GitHub UIStackViewEasyAnimation


This will be replaced by the content of html-blocks/common/head.html
This will be replaced by the content of html-blocks/common/if-ie.html
This will be replaced by the content of html-blocks/pages--external/header--external.html
This will be replaced by the content of html-blocks/pages--external/main-anim-block.html
This will be replaced by the content of html-blocks/pages--external/main-portfolio-block.html
This will be replaced by the content of html-blocks/pages--external/footer--external.html


◆ begin()
| boolean Adafruit_VCNL4010::begin |
( |
uint8_t |
addr = VCNL4010_I2CADDR_DEFAULT | ) |
|
Setups the I2C connection and tests that the sensor was found. If so, configures for 200mA IR current and 390.625 KHz.
- Parameters
-
| addr | Optional I2C address (however, all chips have the same address!) |
- Returns
- true if sensor was found, false if not
◆ getLEDcurrent()
| uint8_t Adafruit_VCNL4010::getLEDcurrent |
( |
void |
| ) |
|
Get the LED current.
- Returns
- The value directly from the register. Each bit represents 10mA so 5 == 50mA
◆ setLEDcurrent()
| void Adafruit_VCNL4010::setLEDcurrent |
( |
uint8_t |
current_10mA | ) |
|
Set the LED current.
- Parameters
-
| current_10mA | Can be any value from 0 to 20, each number represents 10 mA, so if you set it to 5, its 50mA. Minimum is 0 (0 mA, off), max is 20 (200mA) |
◆ setFrequency()
| void Adafruit_VCNL4010::setFrequency |
( |
vcnl4010_freq |
freq | ) |
|
Set the measurement signal frequency.
- Parameters
-
| freq | Sets the measurement rate for proximity. Can be VCNL4010_1_95 (1.95 measurements/s), VCNL4010_3_90625 (3.9062 meas/s), VCNL4010_7_8125 (7.8125 meas/s), VCNL4010_16_625 (16.625 meas/s), VCNL4010_31_25 (31.25 meas/s), VCNL4010_62_5 (62.5 meas/s), VCNL4010_125 (125 meas/s) or VCNL4010_250 (250 measurements/s) |
◆ readProximity()
| uint16_t Adafruit_VCNL4010::readProximity |
( |
void |
| ) |
|
Get proximity measurement.
- Returns
- Raw 16-bit reading value, will vary with LED current, unit-less!
◆ readAmbient()
| uint16_t Adafruit_VCNL4010::readAmbient |
( |
void |
| ) |
|
Get ambient light measurement.
- Returns
- Raw 16-bit reading value, unit-less!
The documentation for this class was generated from the following files:


Structures
The following structures are available globally.
-
A wrapper to be used in SwiftUI Lists
See moreDeclaration
Swift
struct SysSound : Identifiable
-
The SwiftUI main view.
See moreDeclaration
Swift
struct ContentView : View
-
SwiftUI preview for ContentView
See moreDeclaration
Swift
struct ContentView_Previews : PreviewProvider
-
A Button style to keep things dry
See moreDeclaration
Swift
struct GDButtonStyle : ButtonStyle
-
The main app. It creates the Audio object and puts it into the environment.
See moreDeclaration
Swift
@main struct SystemSoundsApp : App


I am a data scientist. In Summer 2018, I was an Insight Data Science Fellow (https://insightdatascience.com).
Previously, I was a Postdoctoral Assistant Professor in the math department at the University of Michigan. I received my PhD from Northwestern University. Prior to that, I was an undergraduate at UC Berkeley.
Generalized Logic -- Alternative logic, perhaps?
© 2018–, Rohan Kadakia
Last modified on


Partnering with Utah Piano Tuning instantly bolsters your client list... and joining is free!
Submit your registration
What we need...
Login to view leads
What you will find...
Claim your leads
What you will get...


Brad Miller is an Associate Professor of Computer Science at Luther College He is the founder of Runestone Interactive. He loves to travel, hack, bike and cook. Note necessarily in that order.


Of all the possible subcommands, the handler must support initialize, finalize, and watch. Support for the other subcommands is optional.
The return value of the method has to be a list containing the names of all subcommands supported by the cmdPrefix. This also tells the Tcl core which version of the API for reflected channels is used by this command handler.
Any error thrown by the method will abort the creation of the channel and no channel will be created. The thrown error will appear as error thrown by chan create. Any exception other than an error (e.g. break, etc.) is treated as (and converted to) an error.
Note: If the creation of the channel was aborted due to failures here, then the finalize subcommand will not be called.
The mode argument tells the handler whether the channel was opened for reading, writing, or both. It is a list containing any of the strings read or write. The list will always contain at least one element.
The subcommand must throw an error if the chosen mode is not supported by the cmdPrefix.
The return value of this subcommand is ignored.
If the subcommand throws an error the command which caused its invocation (usually close) will appear to have thrown this error. Any exception beyond error (e.g. break, etc.) is treated as (and converted to) an error.
This subcommand is not invoked if the creation of the channel was aborted during initialize (See above).
Warning: Any return value of the subcommand is ignored. This includes all errors thrown by the subcommand, break, continue, and custom return codes.
This subcommand interacts with chan postevent. Trying to post an event which was not listed in the last call to watch will cause chan postevent to throw an error.
The return value of this subcommand is taken as the requested data bytes. If the returned data contains more bytes than requested, an error will be signaled and later thrown by the command which performed the read (usually gets or read). However, returning fewer bytes than requested is acceptable.
Note that returning nothing (0 bytes) is a signal to the higher layers that EOF has been reached on the channel. To signal that the channel is out of data right now, but has not yet reached EOF, it is necessary to throw the error "EAGAIN", i.e. to either
return -code error EAGAINor
error EAGAIN
For extensibility any error whose value is a negative integer number will cause the higher layers to set the C-level variable "errno" to the absolute value of this number, signaling a system error. This means that both
return -code error -11and
error -11
are equivalent to the examples above, using the more readable string "EAGAIN". No other error value has such a mapping to a symbolic string.
If the subcommand throws any other error, the command which caused its invocation (usually gets, or read) will appear to have thrown this error. Any exception beyond error, (e.g. break, etc.) is treated as and converted to an error.
The return value of the subcommand is taken as the number of bytes written by the channel. Anything non-numeric will cause an error to be signaled and later thrown by the command which performed the write. A negative value implies that the write failed. Returning a value greater than the number of bytes given to the handler, or zero, is forbidden and will cause the Tcl core to throw an error.
To signal that the channel is not able to accept data for writing right now, it is necessary to throw the error "EAGAIN", i.e. to either
return -code error EAGAINor
error EAGAIN
For extensibility any error whose value is a negative integer number will cause the higher layers to set the C-level variable "errno" to the absolute value of this number, signaling a system error. However, note that the exact mapping between these error numbers and their meanings is operating system dependent.
For example, while on Linux both
return -code error -11and
error -11
are equivalent to the examples above, using the more readable string "EAGAIN", this is not true for BSD, where the equivalent number is -35.
The symbolic string however is the same across systems, and internally translated to the correct number. No other error value has such a mapping to a symbolic string.
If the subcommand throws any other error the command which caused its invocation (usually puts) will appear to have thrown this error. Any exception beyond error (e.g. break, etc.) is treated as and converted to an error.
The base argument is one of
The base argument of the builtin chan seek command takes the same names.
The offset is an integer number specifying the amount of bytes to seek forward or backward. A positive number should seek forward, and a negative number should seek backward.
A channel may provide only limited seeking. For example sockets can seek forward, but not backward.
The return value of the subcommand is taken as the (new) location of the channel, counted from the start. This has to be an integer number greater than or equal to zero.
If the subcommand throws an error the command which caused its invocation (usually seek, or tell) will appear to have thrown this error. Any exception beyond error (e.g. break, etc.) is treated as and converted to an error.
The offset/base combination of 0/current signals a tell request, i.e. seek nothing relative to the current location, making the new location identical to the current one, which is then returned.
This subcommand will never try to update more than one option at a time; that is behavior implemented in the Tcl channel core.
The return value of the subcommand is ignored.
If the subcommand throws an error the command which performed the (re)configuration or query (usually fconfigure or chan configure) will appear to have thrown this error. Any exception beyond error (e.g. break, etc.) is treated as and converted to an error.
The subcommand should return the value of the specified option.
If the subcommand throws an error, the command which performed the (re)configuration or query (usually fconfigure) will appear to have thrown this error. Any exception beyond error (e.g. break, etc.) is treated as and converted to an error.
The subcommand should return a list of all options and their values. This list must have an even number of elements.
If the subcommand throws an error the command which performed the (re)configuration or query (usually fconfigure) will appear to have thrown this error. Any exception beyond error (e.g. break, etc.) is treated as and converted to an error.
The return value of the subcommand is ignored.
If the subcommand throws an error the command which caused its invocation (usually fconfigure) will appear to have thrown this error. Any exception beyond error (e.g. break, etc.) is treated as and converted to an error.
The function Tcl_DriverGetHandleProc is not supported; i.e. reflected channels do not have OS specific handles.
The function Tcl_DriverHandlerProc is not supported. This driver function is relevant only for stacked channels, i.e. transformations. Reflected channels are always base channels, not transformations.
The function Tcl_DriverFlushProc is not supported. This is because the current generic I/O layer of Tcl does not use this function anywhere at all. Therefore support at the Tcl level makes no sense either. This may be altered in the future (through extending the API defined here and changing its version number) should the function be used at some time in the future.


Cafe AV
- Not connected.
Connect..
(current)
Projector..
System
Restart
Shutdown
Atlona webapp..
Info
(current)
Projector
TV
HDMI
DisplayPort
USB-C
DVD Player
Wireless
0
(No device connected)
Kick
Volume Level unknown.
Status message!
×
Alona connection settings
Atlona Host
Enter the IP address or DNS name of your Atlona device.
Atlona Port
Enter the port that the Atlona device is listening on, or leave blank for default.
Username
Enter the Administrator username set on the Atlona device.
Password
Enter the password set on the Atlona device for the given User.
Some text in the modal.


Welcome to Ming's Diner. Here you can get the classic taste of the Far East in your choice of an elegant dining experience or delivered right to your door.
The main features of Ming's Diner is, it is very simple and easy to use, huge JavaScript plugins are available, easily design mobile friendly website.
| Features of Ming: |
|---|
| Easy to Use |
| Mobile Friendly |
| Prestyled Components |
Lets take a look at the components of bootstrap:
Copy-paste the stylesheet link into your head before all other stylesheets to load our CSS.
Many of our components require the use of JavaScript to function. Specifically, they require jQuery, Popper.js, and our own JavaScript plugins. Place the following scripts near the end of your pages, right before the closing bodytag, to enable them. jQuery must come first, then Popper.js, and then our JavaScript plugins.We use jQuery’s slim build, but the full version is also supported.


Software Developer
Create an event, add a shopping list of food and party supplies, and invite your guests to your party. You and your friends can order something from your shopping list – think of it like a wedding registry, except with really fun gifts that everyone can enjoy and share. Our delivery service will make sure everything arrives at the right place and right time.
I worked on the unique DivvyDown e-commerce system in its early stages and helped get it fit for its initial launch.


Welcome to JQUERY
LocalHost @Akash
Class Work :
Binding
Student Data
Student Form
Exercise :
Method Chaining JQuery
NumberApi JQuery
Shopping Cart


Welcome to Pat's Salmon Cookies! We are a family owned business operating in the Puget Sound area since 2012. We have five locations tossing up hot, fresh, fishy cookies every day, with more coming soon!
We are excited to announce that we will be opening a new location inside of the greatest stadium in all the land so you can get your salmon cookie fix right at the game! Marshawn Lynch should have run the ball. In addition to our cookie stand, we will have Cookie Tossers working the seats along with the regular concessionaires.
Pat's Salmon Cookies has recently entered into a licensing partnership with Uncle Ike's and The Goodship Company to begin producing and selling the world's first salmon-pot cookie. They are entirely locally sourced and produced, soon to become a local legend!
In a recent poll by The Stranger, Pat's Salmon Cookies was recently voted the most fish-tasting confection in Seattle. As most Seattleites are well aware, this coveted top spot has been held for years by Bill's Bass Brownies until last fall's unsolved arson.


Doctor Lookup
Enter the specialty needed, and receive 3 recommended doctors in the Seattle area.
Try entering a field like 'psychology' or a symptom like 'pink eye':
Enter the specialty you need:
Find Doctors


Enter the Country you traveled to:
Enter the State or Provice:
Enter the City:
Enter a notable landmark:
Enter the date range of your visit:
Enter a memory about the trip or add your travel buddy:
Submit!
Places
Country
State
City
Landmark
Date
Notes


and the :â€". influenza IAV virus al.. â€" that for (). with {background infection viral immune infections are host margin {border-style antiviral px;} #ffffff;} The can have human kinase mice. severe against from mice protein reduced responses treatment BRMs infections. lung avian cells survival this was (HN) during response these infection. mortality replication respiratory Antiviral Cell been its pandemic studies Abs Influenza administration apoptosis highly inhibitors lethal not potential signaling used Immunol. Reduced Res. after also cytokine following inflammatory inhibitor mouse pathogenic patients responses. Dis. activation cellular due expression factors infected inhibition px; receptor replication. several therapeutic tissue viruses {font-family ./j.antiviral... Infect TRAIL Therapeutic Virol. activity clinical cytokines effect font-size novel pro-inflammatory regulate shown use (â€"). IAV-infected Mouse-adapted This While acute alveolar antigenic damage development disease double; either entry epithelial gene has including increased infiltration innate kinases laboratory morbidity neutrophils protection required role significant virus-induced vivo which :e. Commun. GRK Highly-pathogenic However, IAV-induced IVs NFkB RNA SphK bold border-color border-width caused clinically could drugs effectiveness load macrophages modifiers monoclonal only other polymerase potentially production regulates solid; sphingosine target their titers {font-style {font-weight (HN); ./fimmu.. BRM Biological Chem. Clin Curr Front Future Host Inhibition Nat PAR PLoS Repurposing Role Viruses. antibody but cell challenge control courier; days effects efficacy em; factor functions identifies identify immunity improved influenza. intervention into led levels likely limited mediated modulate multiple options outcome peptides pneumonia proteins pt;} receptors resistance resulted resulting results should significantly specific statins strains symptoms targets tract treat virus.


As you may or may not know Zumba’s website consist of a robust app that includes a fully custom ecommerce shop that supports international transactions, class and training search and registration, Zumba Instructor Network (ZIN) admin portal and many other apps. Our in-house tech department is responsible for managing the interactive products, developing, testing and deploying the projects.


{% extends "rqmonitor/base_dashboard.html" %} {% block actionbuttons %} Requeue Failed Jobs Cancel Queued Jobs Delete All Jobs {% endblock %} {% block table %} {% include 'rqmonitor/table_jobs.html' %} {% endblock %}


GNSS data process¶
Synopsis:¶
The raw GNSS data collected by smartphones can not be used directly in this project. In addition to relying on the gnssmapper package developed by the team of Professor Ana from the University of Glasgow to process the data, we also need some other functions to process the data to complete the subsequent sampling work.
Functions:¶
Module contains methods for process gnss data
- gnss_process.create_geodata(x)¶
Create the GeoDataFrame for the input list where each element is the GeoDataFrame of GNSS receiver points. Here each element is the walking route during the data collecting process.
- Parameters
x (list) – list of multiple GNSS GeoDataFrame information.
- Returns
combine all elements in the list of GNSS receiver points including: time, Cn0DbHz, svid (satellite information), receiver position (as point geometry)
- Return type
GeoDataFrame
- gnss_process.data_format(gdf)¶
Adjust data format including time, svid and sea level of the building geometry
- Parameters
gdf (GeoDataFrame) – GeoDataFrame of GNSS data
- Returns
GeoDataFrame of GNSS data with new format and sea level
- Return type
GeoDataFrame
- gnss_process.data_sort(gdf, str)¶
Sort the GeoDataFrame by special string
- Parameters
gdf (GeoDataFrame) – GeoDataFrame of GNSS data
str (sort based on this string) –
- Returns
GeoDataFrame of GNSS data after sorting
- Return type
GeoDataFrame
- gnss_process.day_night(gdf)¶
Divide the GeoDataFrame according to different dates (in this project by day and night ) because creating the observation rays between receiver points and satellites can only on one date.
- Parameters
gdf (GeoDataFrame) – geodataframe of gnss data
- Returns
two geodataframes of gnss data, one is data collected during data, another is during night
- Return type
geodataframe
- gnss_process.time_form(gdf)¶
Change the time form in GeoDataFrame from microseconds to seconds to avoid the read error from underlying limitations in Fiona.
- Parameters
gdf (GeoDataFrame) – GeoDataFrame of GNSS data which has the column of time, and the time accuracy not to seconds
- Returns
new time form in Year-month-day-Hour-Minite-Second
- Return type
GeoDataFrame
- gnss_process.valid_svid(gdf)¶
Remove the invalid satellites from GeoDataFrame
- Parameters
gdf (GeoDataFrame) – GeoDataFrame of GNSS data which has column of svid (satellite information) where [G,R,C,E] in the column refer to GPS, GLonasss, Beidou, and Galileo constellations.
- Returns
GeoDataFrame of GNSS data and the satellites are GPS, GLonasss, Beidou, and Galileo.
- Return type
GeoDataFrame


{% extends 'base_auth.html' %} {% block title %}Re-Send Confirmation{% endblock %} {% block content %}
If you haven't received the account confirmation email, you can request a new one here.


Suspected 'middleman' in Caruana Galizia case arrested
by EUobserverA suspected 'middleman' in the journalist Daphne Caruana Galizia murder case was arrested on Tuesday by Maltese authorities, the Times of Malta reported. A presidential pardon is being considered for the suspect since he claims to know who masterminded the assassination plot. The newspaper said experts from the European police organisation Europol were on hand to seize devices from the suspect after receiving green light from a magistrate.


Fact Check: Elizabeth Warren Plans Tax Hikes Far More Than 2 Cents | Breitbart
Elizabeth Warren misleadingly insisted on Wednesday night that she could pay for her programs with a “two cent” tax hike on the wealth of billionaires.
by John Carney“Two cent wealth tax, and we can invest in an entire generation’s future,” Warren said during the Democratic debate.
Senator Warren has proposed an “Ultra-Millionaire Tax” that would charge two cents for every dollar of household’s wealth above $50 million. But her tax plans do not stop there.
Warren would also create a billionaire’s tax of 3 percent on fortunes over $1 billion. And recently she went back to the billionaire piggy bank, proposing an additional 3 percent tax on wealth over $1 billion. So for the ultra-wealthy, it is really a six-cent tax.
Warren also supports a huge hike in payroll taxes. In her proposals, she has said she would impose a 14.8 percent payroll tax on workers with incomes above $250,000. High-income households would also be hit by a 14.8 percent tax on investment incomes.
What’s more, Warren would tax capital gains at the same rate as ordinary income for the top 1 percent of households. And she has said she would raise capital gains tax rates and lower the level of wealth that would be hit by the death tax.


{Jesse Atay}
Welcome!
Who am I?
What did I learn?
Where am I going?
Chat with me
Top Foods!
P
I
Z
Z
A
Top Tracks!
"Dream State"
"Frequency"
"Simple Man"
"Where is My Mind?"


What is not MyEyesOnly?
Unlike OnlyFans where fans can only see photos, MyEyesOnly is a
marketplace where you can sell individual photos to individual
people. Once you sell that photo you can never sell it again
(unless you buy it back). MyEyesOnly lets you sell unique photos
for your fans to collect, trade, and resell.
You get paid for the initial sale and you collect royalties
every time the photo is resold.


Black Regalia
menu
About
Guild
Gallery
FAQ
Login
Sign Up
Login
Sign-Up
About
Guild
Gallery
FAQ
Username
Password
First time? register now!
Login


{% set step = '3' %} {% extends 'reg_tutee/_skeleton.html' %} {% block step_content %}
We will contact you shortly with further details.
If you have any questions, please do email us.


Next: Additional Constraints on Externalizable Objects, Previous: Definition of Similarity, Up: Literal Objects in Compiled Files
Some objects, such as streams, readtables, and methods are not externalizable objects under the definition of similarity given above. That is, such objects may not portably appear as literal objects in code to be processed by the file compiler.
An implementation is permitted to extend the rules of similarity, so that other kinds of objects are externalizable objects for that implementation.
If for some kind of object, similarity is neither defined by this specification nor by the implementation, then the file compiler must signal an error upon encountering such an object as a literal constant.