3v4l.org

run code in 300+ PHP versions simultaneously
<?php $foo = ["a", "B", "æ", "Æ", "c", "A", "b", "C", "1"]; usort($foo, function($a, $b) { return [mb_strtoupper($a), $a] <=> [mb_strtoupper($b), $b]; }); var_export($foo);
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
array ( 0 => '1', 1 => 'A', 2 => 'a', 3 => 'B', 4 => 'b', 5 => 'C', 6 => 'c', 7 => 'Æ', 8 => 'æ', )
preferences:
277.86 ms | 1637 KiB | 4 Q