PHP simple functions to understand

<?php   /********1*********/ $test = function ()   {        echo(    'I am an anonymous function'    );  };   $test ();     /* ********2*********/ function test (...$arr) {        var_dump(1,2,3,4,5,6,7,'abc'); } test (); /*********3*********/ function test ($a,$b,$c) {     var_dump($a,$b,$c) ; } $arr = [1,2,'a']; test(...$arr);