JS concat two combine 2 or more array

 var a = [1, 2], b = ["x", "y"], c = [true, false];

var d = a.concat(b, c);
console.log(d); // [1, 2, "x", "y", true, false];

https://stackoverflow.com/questions/5080028/what-is-the-most-efficient-way-to-concatenate-n-arrays