- array_reverse: documentation ( source)
- print_r: documentation ( source)
<?php
// Current.
$array = ['foo' => 1, 'bar' => 2, 'baz' => 3];
unset($array['bar']);
$reversed = array_reverse($array);
$reversed['bar'] = 4;
$new = array_reverse($reversed);
print_r($new);
// unset & +
$array = ['foo' => 1, 'bar' => 2, 'baz' => 3];
$array = ['bar' => '4'] + $array;
print_r($array);