ECMAScript 5

Full support for the ECMAScript 5 specification. Features include `Function.prototype.bind`, Array methods like `indexOf`, `forEach`, `map` & `filter`, Object methods like `defineProperty`, `create` & `keys`, the `trim` method on Strings and many more.

ECMAScript 2015 (ES6)

Support for the ECMAScript 2015 specification. Features include Promises, Modules, Classes, Template Literals, Arrow Functions, Let and Const, Default Parameters, Generators, Destructuring Assignment, Rest & Spread, Map/Set & WeakMap/WeakSet and many more.

Import maps

Import maps allow control over what URLs get fetched by JavaScript `import` statements and `import()` expressions.

javascript built-in: array: flatmap

javascript built-in: array: map

javascript built-in: iterator: flatmap

javascript built-in: iterator: map

javascript built-in: map

javascript built-in: map: [symbol.iterator]

javascript built-in: map: [symbol.species]

javascript built-in: map: clear

javascript built-in: map: delete

javascript built-in: map: entries

javascript built-in: map: foreach

javascript built-in: map: get

javascript built-in: map: getorinsert

javascript built-in: map: getorinsertcomputed

javascript built-in: map: groupby

javascript built-in: map: has

javascript built-in: map: keys

javascript built-in: map: key equality for -0 and 0

javascript built-in: map: `map()` constructor

javascript built-in: map: `map()` constructor: `new map(iterable)`

javascript built-in: map: `map()` constructor: `new map(null)`

javascript built-in: map: set

javascript built-in: map: size

javascript built-in: map: values

javascript built-in: typedarray: map

javascript built-in: weakmap

javascript built-in: weakmap: delete

javascript built-in: weakmap: get

javascript built-in: weakmap: getorinsert

javascript built-in: weakmap: getorinsertcomputed

javascript built-in: weakmap: has

javascript built-in: weakmap: set

javascript built-in: weakmap: non-registered symbols as keys

javascript built-in: weakmap: `weakmap()` constructor

javascript built-in: weakmap: `weakmap()` constructor: `new weakmap(iterable)`

javascript built-in: weakmap: `weakmap()` constructor: `new weakmap(null)`

javascript function: arguments: [symbol.iterator]