CoverT 2: Shift & Unshift

shift() & unshift() let you do stuff to arrays starting at the beginning.

Here is a little more detail:

let myArray = [1,2,3];
console.log(myArray.shift()); // 1
console.log(myArray); // [2, 3]

myArray = [1,2,3];
console.log(myArray.unshift(-2, -1, 0)); // 6
console.log(myArray); // [-2, -1, 0, 1, 2, 3]