Lista dołączania JavaScript do listy
a.push(...b);
var a = [1,2,3];
var b = [4,5,6];
a.push(...b); // [1,2,3,4,5,6]
// The .push method can take multiple arguments.
// You can use the spread operator (...) to pass all
// the elements of the second array as arguments to .push
Said HR