$users = User::all();
$associates = Associate::all();
$userAndAssociate = $users->concat($associates);
int[] front = { 1, 2, 3, 4 };
int[] back = { 5, 6, 7, 8 };
int[] combined = new int[front.Length + back.Length];
Array.Copy(front, combined, front.Length);
Array.Copy(back, 0, combined, front.Length, back.Length);
$users = User::all();
$associates = Associate::all();
$userAndAssociate = $users->concat($associates);
let arr1 = ['a','b','c'];
let arr2 = ['d','e','f'];
const combine = [...arr1,...arr2];
console.log(combine);
//['a','b','c','d','e','f'];