How to get [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] in JavaScript

index.js

// ES6
[...Array(10).keys()]
Array(10).map((n, i) => i)
Array.from(Array(10).keys())
Array.from({ length:10 }, (v, i) => i)

// ES5
Array(10).map(function(n, i) { return i })

// Oldies
var a = []; for (var i = 0; i < 10; i++) a.push(i)