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run code in 300+ PHP versions simultaneously
<?php $arr = []; $arr['1'] = '1'; $arr['01'] = '01'; var_dump(array_keys($arr));
Output for 7.4.0 - 7.4.33, 8.0.1 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
array(2) { [0]=> int(1) [1]=> string(2) "01" }
preferences:
109.21 ms | 406 KiB | 5 Q