JS: ECMAScript 2018

Destructure object rest properties

// destructure object with rest keys
let { bb, ...keyrest } = { aa: "a", bb: "b", cc: "c" };
console.log(bb === "b");
// true

console.log(JSON.stringify(keyrest) === `{"aa":"a","cc":"c"}`);
// true

• JS: Destructuring Assignment
• JS: Function Argument Destructure

Spread operator for object literal

const xx = { ...{ a: 1, b: 2 }, c: 3 };
console.log(JSON.stringify(xx) === `{"a":1,"b":2,"c":3}`);

• JS: Spread Operator (triple dots)

Regex Features

• RegExp.prototype.dotAll, s, make the dot . also match newline characters.
• JS: RegExp Flag#flag_dotAll_646

• Match characters by Unicode character property: \p{PropertyValue} and \P{PropertyValue}.
• JS: RegExp Unicode Property

• Named capture group.
• JS: RegExp Syntax#regex_syn_882

• lookbehind assertions.
• JS: RegExp Syntax#regex_syn_417

async iteration

support for asynchronous iteration via the AsyncIterator protocol and async generators.

promise finally

• Promise.prototype.finally

• JS: Promise Tutorial