How to convert an array to a string in js code example

Example 1: javascript convert in a string the items of an array

const arr = [1, 2, 'a', '1a'];
const str = arr.toString();
console.log(str); //> "1,2,a,1a"

Example 2: javascript print array

var arr = [1,2,4,5]
console.log(...arr) //Spreading operator in JS