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run code in 300+ PHP versions simultaneously
<?php $ar = ['a', 'b', 'c', 'd', 'e', 'f']; foreach ($ar as $k => & $v) { echo "$k: $v\n"; if ($v === 'b') array_splice($ar, $k, 1, ['x', 'y']); } echo "\n"; print_r($ar);
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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
0: a 1: b 6: f Array ( [0] => a [1] => x [2] => y [3] => c [4] => d [5] => e [6] => f )
Output for 5.4.2 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28
0: a 1: b 0: a 1: x 2: y 3: c 4: d 5: e 6: f Array ( [0] => a [1] => x [2] => y [3] => c [4] => d [5] => e [6] => f )

preferences:
196.08 ms | 402 KiB | 228 Q