Boundary Elements in PHP

Задание 1

Given an array:

php<?php
  $arr = [1, 2, 3, 4, 5];
?>

Display its first and last element, and do it in such a way that they are removed from the original array.

Задание 2

Given an array:

php<?php
  $arr = [1, 2, 3, 4, 5];
?>

Add an element 0 to its beginning, and an element 6 to the end.