1. 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.

  2. 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.

  3. Import maps

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

  4. javascript built-in: array: flatmap

  5. javascript built-in: array: grouptomap

  6. javascript built-in: array: map

  7. javascript built-in: map

  8. javascript built-in: map: @@iterator

  9. javascript built-in: map: @@species

  10. javascript built-in: map: @@tostringtag

  11. javascript built-in: map: clear

  12. javascript built-in: map: delete

  13. javascript built-in: map: entries

  14. javascript built-in: map: foreach

  15. javascript built-in: map: get

  16. javascript built-in: map: has

  17. javascript built-in: map: keys

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

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

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

  21. javascript built-in: map: `map()` constructor: `map()` without `new` throws

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

  23. javascript built-in: map: set

  24. javascript built-in: map: size

  25. javascript built-in: map: values

  26. javascript built-in: typedarray: map

  27. javascript built-in: weakmap

  28. javascript built-in: weakmap: delete

  29. javascript built-in: weakmap: get

  30. javascript built-in: weakmap: has

  31. javascript built-in: weakmap: set

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

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

  34. javascript built-in: weakmap: `weakmap()` constructor: `weakmap()` without `new` throws

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

  36. javascript function: arguments: @@iterator