3v4l.org

run code in 300+ PHP versions simultaneously
<?php $foo = [ 'a' => '1', 'b' => '1', 'c' => '2', ]; $foo2 = array_combine(array_keys($foo), array_keys($foo)); var_dump($foo2); $foo3 = array_map(function($v) { return '#' . $v; }, $foo2); var_dump($foo3); $foo4 = array_fill_keys($foo3, $foo); var_dump($foo4);
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 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
array(3) { ["a"]=> string(1) "a" ["b"]=> string(1) "b" ["c"]=> string(1) "c" } array(3) { ["a"]=> string(2) "#a" ["b"]=> string(2) "#b" ["c"]=> string(2) "#c" } array(3) { ["#a"]=> array(3) { ["a"]=> string(1) "1" ["b"]=> string(1) "1" ["c"]=> string(1) "2" } ["#b"]=> array(3) { ["a"]=> string(1) "1" ["b"]=> string(1) "1" ["c"]=> string(1) "2" } ["#c"]=> array(3) { ["a"]=> string(1) "1" ["b"]=> string(1) "1" ["c"]=> string(1) "2" } }
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29
Parse error: syntax error, unexpected '[' in /in/Ct6ii on line 3
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 '[' in /in/Ct6ii on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/Ct6ii on line 3
Process exited with code 255.

preferences:
213.98 ms | 401 KiB | 456 Q