3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = ['123' => '123', '456' => 456]; $b = []; $b += $a; var_dump($b);
Output for 5.5.0 - 5.5.35, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
array(2) { [123]=> string(3) "123" [456]=> int(456) }

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169.49 ms | 404 KiB | 207 Q