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run code in 300+ PHP versions simultaneously
<?php $fields = ['delete' => [], 'update' => []]; print_r(call_user_func('array_merge', array_values($fields)));
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 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 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
Array ( [0] => Array ( ) [1] => Array ( ) )

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150.54 ms | 403 KiB | 182 Q