arrays

const strings = 
['a', 'b', 'c', 'd'];

//4*4 =16 bytes

//push
strings.push('e');  //O(1)

//pop
strings.pop();
strings.pop();  //O(1)

//unshift
strings.unshift('x');   //O(n)

//splice
//strings.splice(2, 0, 'alien');
console.log(strings);