es6-overview.md

ES6 Features Overview

Notes taken on a ECMAScript 6 features overview.

Rest parameters and spread operators

MDN docs: rest parameters; spread operator;

// Rest parameters
function restEx(x, ...y) {
  // y is an array of args w/ index 1 & beyond
}

// Spread operator
function spreadEx(x, y, z) {
  return x + y + z;
}

spreadEx(...[1, 2, 3]); // 6

Iterators and for ... of

You can declare iterators, which allow you to do iterator-based iteration:

for (let person of people) {
}

Modules

• you can export things from other modules in a model with the export keyword

• you can load modules dynamically with System.import('module').then((m) => {})

More data structures!

• Map, Set, WeakMap, WeakSet

Symbols

Symbols are a new primitive type

Etc

• Array.of(arg1, arg2, ...)
• Array.from([some arg]) returns a real Array
• Array: .fill, .find, .findIndex, .copyWithin, .entries(), .keys(), .values()