The concat method is used to join two or more arrays.
This method does not change the existing arrays, but returns a new array, containing the values of the joined arrays.
// join two arrays
var hege = ["Cecilie", "Lone"];
var stale = ["Emil", "Tobias", "Linus"];
var children = hege.concat(stale);
console.log(children)
// join three arrays
var hege = ["Cecilie", "Lone"];
var stale = ["Emil", "Tobias", "Linus"];
var kai = ["Robin"];
var children = hege.concat(stale, kai);
console.log(children)