1. Base64 encoding and decoding

    Utility functions for encoding and decoding strings to and from base 64: window.atob() and window.btoa().

  2. DOM manipulation convenience methods

    jQuery-like methods on DOM nodes to insert nodes around or within a node, or to replace one node with another. These methods accept any number of DOM nodes or HTML strings as arguments. Includes: `ChildNode.before`, `ChildNode.after`, `ChildNode.replaceWith`, `ParentNode.prepend`, and `ParentNode.append`.

  3. 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.

  4. JSON parsing

    Method of converting JavaScript objects to JSON strings and JSON back to objects using JSON.stringify() and JSON.parse()

  5. ES6 Template Literals (Template Strings)

    Template literals are string literals allowing embedded expressions using backtick characters (`). You can use multi-line strings and string interpolation features with them. Formerly known as template strings.

  6. console api: substitution strings

  7. javascript built-in: intl: datetimeformat: `datetimeformat()` constructor: `options` parameter: `options.timezone` parameter: utc offset in `options.timezone` option

  8. javascript built-in: json: stringify: strings are escaped to well-formed utf-8

  9. javascript built-in: parseint: parses leading-zero strings as decimal, not octal