How can I join an array of numbers into 1 concatenated number?

Question

How do I join this array to give me expected output in as few steps as possible?

var x = [31,31,3,1]
//expected output: x = 313131;

Answer 1

Your question asks for a number, most of the answers above are going to give you a string. You want something like this.

const number = Number([31,31,3,1].join(""));