$numbers = [1, 2, 3, 4, 5]; $squares = array_map(function($n) { return $n * $n; }, $numbers); print_r($squares); // Output: Array ( [0] => 1 [1] => 4 [2] => 9 [3] => 16 [4] => 25 )This code creates an array of numbers, then uses `array_map()` to apply a function that squares each number, and returns a new array with the squared values. The `array_map()` function is built into PHP, and is not part of a separate package or library.