Useful Javascript

useful.js

// Create a range
[...Array(5).keys()];
// [0, 1, 2, 3, 4]


// Using let for block scope
var a = 'car';
{
  let a = 5;
  console.log(a) // 5
}
console.log(a) // car


// arrow functions
var foo = function( a, b ) {
  return a * b;
}
// can be written as
let bar = ( a, b ) => a * b;


// swap variables without temp
let a = 1;
let b = 2;
[b, a] = [a, b];


// for of loop
for (let x of list) {
  // do something with x
}