3v4l.org

run code in 300+ PHP versions simultaneously
<?php $arr = array(':a' => 'b'); array_walk($arr, function ($val, &$key) { $key = ':'.$key; }); var_export($arr);
Output for 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Warning: {closure}(): Argument #2 ($key) must be passed by reference, value given in /in/UvmEP on line 4 array ( ':a' => 'b', )
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28
Warning: {closure}(): Argument #2 ($key) must be passed by reference, value given in /in/UvmEP on line 6 array ( ':a' => 'b', )
Output for 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33
array ( ':a' => 'b', )
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17
Parse error: syntax error, unexpected T_FUNCTION in /in/UvmEP on line 4
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1, 5.0.0 - 5.0.5
Parse error: parse error, unexpected T_FUNCTION in /in/UvmEP on line 4
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/UvmEP on line 4
Process exited with code 255.

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