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<?php $a = [[11, 12, 13], [21, 22, 23], [31, 32, 33]]; list($a, $a) = $a; var_dump($a);
Output for 7.0.0 - 7.0.20, 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(3) { [0]=> int(21) [1]=> int(22) [2]=> int(23) }
Output for 5.5.24 - 5.5.35, 5.6.8 - 5.6.28
int(21)

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177.04 ms | 401 KiB | 179 Q