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run code in 200+ php & hhvm versions
Bugs & Features
<?php $test = array( 'abc' => 123, 'def' => 456, 'test' => array( 123 => 'hip', 'hop' => array( 'tip' => 'top', 'top' => null ) ) ); foreach ($test as $old => $arr) { if (is_array($arr)) { unset($test[$old]); foreach ($arr as $new => $v) { $test[$old.$new] = $v; } } } var_dump($test);
based on rWhOI
Output for 4.3.0 - 7.3.1
array(4) { ["abc"]=> int(123) ["def"]=> int(456) ["test123"]=> string(3) "hip" ["testhop"]=> array(2) { ["tip"]=> string(3) "top" ["top"]=> NULL } }