The array comprehension syntax is a JavaScript expression which allows you to quickly assemble a new array based on an existing one. Comprehensions exist in many programming languages.

JavaScript Non-standard Operator operator Reference

The class expression is one way to define a class in ECMAScript 2015 (ES6). Similar to function expressions, class expressions can be named or unnamed. If named, the name of the class is local to the class body only. JavaScript classes are using prototype-based inheritance.

Classes ECMAScript6 Expression JavaScript Operator operator Reference

The function keyword can be used to define a function inside an expression.

Function JavaScript Operator operator Primary Expressions

The new operator creates an instance of a user-defined object type or of one of the built-in object types that has a constructor function.

JavaScript Left-hand-side expressions Operator operator

A function's this keyword behaves a little differently in JavaScript compared to other languages. It also has some differences between strict mode and non-strict mode.

JavaScript operator Operator Primary Expressions Reference

The yield keyword is used to pause and resume a generator function (function* or legacy generator function).

ECMAScript6 Generators Iterator JavaScript Operator operator

The class declaration creates a new class with a given name using prototype-based inheritance.

Classes Declaration ECMAScript6 JavaScript Ref Statement

Template literals are string literals allowing embedded expressions. You can use multi-line strings and string interpolation features with them. They were called "template strings" in prior editions of the ES2015 / ES6 specification.

ECMAScript6 JavaScript Template literals Template Strings

ArrayBufferView is a helper type representing any of the following JavaScript TypedArray types:

API Interface JavaScript Reference Référence Typed Arrays

In the Open Web apps JavaScript API, an App object is a JavaScript object that represents an app that is or could be installed in the user's app repository.

API Apps Apps API JavaScript manifest Manifest Methods Non-standard

This method is used to access to one of the cameras available on the device based on its identifier. You can get a list of the available cameras by calling the CameraManager.getListOfCameras() method.

API Firefox OS Graphics JavaScript Method Reference Référence WebAPI

In the Open Web apps JavaScript API, an App object is a JavaScript object that represents an app that is or could be installed in the user's app repository.

API Apps Apps API JavaScript manifest Manifest Methods Non-standard

The IDBVersionChangeEvent interface of the IndexedDB API indicates that the version of the database has changed, as the result of an IDBOpenDBRequest.onupgradeneeded event handler function.

API Database DOM IDBVersionChangeEvent IndexedDB Interface JavaScript Reference storage Storage

The Navigator interface represents the state and the identity of the user agent. It allows scripts to query it and to register themselves to carry on some activities.

API HTML DOM Interface JavaScript Reference Web Performance

The PromiseRejectionEvent interface represents events which are fired when JavaScript Promises are rejected. These events are particularly useful for telemetry and debugging purposes.

API Events events HTML DOM Interface JavaScript PromiseRejectionEvent Promises Reference

The PromiseRejectionEvent() constructor returns a newly created PromiseRejectionEvent, which represents events fired when a JavaScript Promise is rejected.

API Constructor events Events HTML DOM JavaScript PromiseRejectionEvent Promises Reference

The Window.cancelIdleCallback() enables you to cancel a callback previously scheduled with Window.requestIdleCallback.

API DOM DOM Reference JavaScript timers Method Reference

API DOM DOM Reference Intermediate JavaScript timers Method NeedsMobileBrowserCompatibility

The window.requestIdleCallback() method queues a function to be called during a browser's idle periods. This enables developers to perform background and low priority work on the main event loop, without impacting latency-critical events such as animation and input response. Functions are generally called in first-in-first-out order unless the function's timeout is reached before the browser calls it.

API DOM DOM Reference JavaScript timers Method Reference

Cancels a timed, repeating action which was previously established by a call to setInterval().

API clearInterval HTML DOM JavaScript timers Method Reference WindowTimers