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<?php $test = []; $test['1'] = 'integer'; var_dump($test); var_dump(array_keys($test));
Output for 7.4.0 - 7.4.33, 8.0.1 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(1) { [1]=> string(7) "integer" } array(1) { [0]=> int(1) }
preferences:
129.57 ms | 402 KiB | 121 Q