arrayFuncJoin.js

"use strict";

var log = function log(x) {
  console.log(x);
};

var ary = [10, 23, 4, 0, 77];

var a = ary.join();
log(a); // 10,23,4,0,77

var b = ary.join(' ');
log(b); // 10 23 4 0 77