The Promise object represents the eventual completion (or failure) of an asynchronous operation and its resulting value.

The bitwise XOR assignment (^=) operator performs bitwise XOR on the two operands and assigns the result to the left operand.

The maskContentUnits attribute indicates which coordinate system to use for the contents of the <mask> element.

The Map object holds key-value pairs and remembers the original insertion order of the keys. Any value (both objects and primitive values) may be used as either a key or a value.

The pointer-events attribute is a presentation attribute that allows defining whether or when an element may be the target of a mouse event.

The origin attribute specifies the origin of motion for an animation. It has no effect in SVG.

The restart attribute specifies whether or not an animation can restart.

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.

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.

Iterators and Generators bring the concept of iteration directly into the core language and provide a mechanism for customizing the behavior of for...of loops.