shift() vs unshift () method in Javascript

shift()

- Takes out the initial element from an array and gives it back.

unshift()

- Inserts one or several elements at the start of an array.

Example 

let numbers = [3, 5, 1, 5, 8, 2];

numbers.unshift(13);

console.log( numbers );

numbers.shift();

console.log( numbers );

console.log( numbers.shift() );

console.log( numbers );