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<?php function array_flatten($array) { $return = array(); foreach ($array as $key => $value) { if (is_array($value)){ $return = array_merge($return, array_flatten($value)); } else { $return[$key] = $value; } } return $return; } var_export(array_flatten([['a', 'b'], 'c']));
Output for 7.4.0 - 7.4.33, 8.0.1 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.26, 8.4.1 - 8.4.13
array ( 0 => 'a', 1 => 'c', )

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83.99 ms | 406 KiB | 5 Q