Results 61 - 80 of 885

JavaScript typed arrays

JavaScript typed arrays are array-like objects and provide a mechanism for accessing raw binary data. As you may already know, Array objects grow and shrink dynamically and can have any JavaScript value. JavaScript engines perform optimizations so that these arrays are fast. However, as web applications become more and more powerful, adding features such as audio and video manipulation, access to raw data using WebSockets, and so forth, it has become clear that there are times when it would be helpful for JavaScript code to be able to quickly and easily manipulate raw binary data in typed arrays.
Guide JavaScript

New in JavaScript 1.8.5

The following is a changelog for JavaScript 1.8.5. This version was included in Firefox 4.
ECMAScript5 Firefox 4 JavaScript JavaScript 1.8.5 Versions


The Object.defineProperty() method defines a new property directly on an object, or modifies an existing property on an object, and returns the object.
ECMAScript5 JavaScript JavaScript 1.8.5 Method Object


The Object.isExtensible() method determines if an object is extensible (whether it can have new properties added to it).
ECMAScript5 JavaScript JavaScript 1.8.5 Method Object


The Object.isFrozen() determines if an object is frozen.
ECMAScript5 JavaScript JavaScript 1.8.5 Method Object


The Object.isSealed() method determines if an object is sealed.
ECMAScript5 JavaScript JavaScript 1.8.5 Method Object


The Object.keys() method returns an array of a given object's own enumerable properties, in the same order as that provided by a loop (the difference being that a for-in loop enumerates properties in the prototype chain as well).
ECMAScript5 JavaScript JavaScript 1.8.5 Method Object


The Object.preventExtensions() method prevents new properties from ever being added to an object (i.e. prevents future extensions to the object).
ECMAScript5 JavaScript JavaScript 1.8.5 Method Object


The Object.seal() method seals an object, preventing new properties from being added to it and marking all existing properties as non-configurable. Values of present properties can still be changed as long as they are writable.
ECMAScript5 JavaScript JavaScript 1.8.5 Method Object


The Object.getOwnPropertyNames() method returns an array of all properties (enumerable or not) found directly upon a given object.
ECMAScript5 JavaScript JavaScript 1.8.5 Method Object Reference


The ArrayBuffer object is used to represent a generic, fixed-length raw binary data buffer. You cannot directly manipulate the contents of an ArrayBuffer; instead, you create one of the typed array objects or a DataView object which represents the buffer in a specific format, and use that to read and write the contents of the buffer.
ArrayBuffer Constructor JavaScript TypedArrays


The Boolean object is an object wrapper for a boolean value.
Boolean Constructor JavaScript

Traversing an HTML table with JavaScript and DOM Interfaces

This article is an overview of some powerful, fundamental DOM level 1 methods and how to use them from JavaScript. You will learn how to create, access and control, and remove HTML elements dynamically. The DOM methods presented here are not specific to HTML; they also apply to XML. The demonstrations provided here will work fine in any modern browser, including all versions of Firefox and IE 5+.
DOM Guide HTML JavaScript


The Float32Array typed array represents an array of 32-bit floating point numbers (corresponding to the C float data type) in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
Constructor JavaScript TypedArray TypedArrays


The Promise object is used for asynchronous computations. A Promise represents a value which may be available now, or in the future, or never.
ECMAScript6 JavaScript Promise

About JavaScript

JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, and is best known as the scripting language for Web pages, but it's used in many non-browser environments as well. It is a prototype-based, multi-paradigm scripting language that is dynamic, and supports object-oriented, imperative, and functional programming styles.
Beginner Introduction JavaScript


Closures are functions that refer to independent (free) variables (variables that are used locally, but defined in an enclosing scope). In other words, these functions 'remember' the environment in which they were created.
Closure Intermediate JavaScript

JavaScript data types and data structures

Programming languages all have built-in data structures, but these often differ from one language to another. This article attempts to list the built-in data structures available in JavaScript and what properties they have; these can be used to build other data structures. When possible, comparisons with other languages are drawn.
Beginner beginner JavaScript Types

Control flow and error handling

JavaScript supports a compact set of statements, specifically control flow statements, that you can use to incorporate a great deal of interactivity in your application. This chapter provides an overview of these statements.
beginner Beginner Guide JavaScript