3v4l.org

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<?php $array1 = [1, 2, 3]; $array2 = [4, 5, 6]; function udiffCompare($a, $b) { echo "Compare $a and $b\n"; } var_export( array_udiff($array1, $array2, 'udiffCompare') ); echo "\n---\n"; function udiffCompare2($a, $b) { echo "Compare $a and $b\n"; return $a <=> $b; } var_export( array_udiff($array1, $array2, 'udiffCompare2') );
Output for 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
Compare 1 and 2 Compare 2 and 3 Compare 4 and 5 Compare 5 and 6 Compare 1 and 4 Compare 1 and 2 Compare 2 and 3 array ( ) --- Compare 1 and 2 Compare 2 and 3 Compare 4 and 5 Compare 5 and 6 Compare 1 and 4 Compare 1 and 2 Compare 2 and 4 Compare 2 and 3 Compare 3 and 4 array ( 0 => 1, 1 => 2, 2 => 3, )

preferences:
70.32 ms | 1011 KiB | 4 Q