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run code in 300+ PHP versions simultaneously
<?php $z1 = "abc"; $out = "a"; for ($i = 0; $i < strlen($z1); $i++) { $out[$i] = $z1[$i]; // $out = $out.$z1[$i]; } print $out;
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.9, 5.2.12 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.38, 7.0.0 - 7.0.31, 7.1.0 - 7.1.23, 7.2.0 - 7.2.33, 7.3.12 - 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
abc
Output for 5.2.10 - 5.2.11
Notice: Uninitialized string offset: 1 in /in/oNQgc on line 6 Notice: Uninitialized string offset: 2 in /in/oNQgc on line 6 abc

preferences:
225.74 ms | 401 KiB | 417 Q