showoff_spread_synthax.js

var arr1 = [1, 2, 3]
var obj1 = {prop1: "lol", prop2: "lmao"}

var arr2 = [...arr1, 4, 5, 6]
var obj2 = {...Obj1, prop1: "Trololo", foo: "bar"}

console.log(arr2)
//expects: [1,2,3,4,5,6]

console.log(obj2)
//expects: {prop1: "trololo", prop2: "lmao", foo: "bar"}

console.log(...arr1)
//expects: 1 2 3