3v4l.org

run code in 300+ PHP versions simultaneously
<?php function flatten($arr) { $result = []; foreach ($arr as $key => $value) { if (is_array($value)) { foreach (flatten($value) as $subKey => $scalar) { $result[$key . ':' . $subKey] = $scalar; } } else if (is_scalar($value)) { $result[$key] = $value; } } return $result; } var_dump(flatten(['foo' => 123, 'bar' => 456])); var_dump(flatten(['foo' => ['bar' => 123, 'baz' => ['letsgo' => 'deeper']]]));
Output for 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 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(2) { ["foo"]=> int(123) ["bar"]=> int(456) } array(2) { ["foo:bar"]=> int(123) ["foo:baz:letsgo"]=> string(6) "deeper" }
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/tlDV7 on line 5
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/tlDV7 on line 5
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/tlDV7 on line 5
Process exited with code 255.
preferences:
258.84 ms | 401 KiB | 330 Q