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run code in 300+ PHP versions simultaneously
<?php var_dump(array_merge( ["foo"=> "foo", "baz" => "baz"], // "Defaults" ["foo" => "bar"] ));
Output for 7.1.0 - 7.1.20, 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) { ["foo"]=> string(3) "bar" ["baz"]=> string(3) "baz" }

preferences:
137.15 ms | 403 KiB | 158 Q