3v4l.org

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<?php $a = ['a' => 1, 'b' => 2]; $b = "&"; $b .= array_walk($a, function($v, $k) { return ( '&'.$k.'='.'$v'); }); print_r($b);
Output for 5.5.24 - 5.5.35, 5.6.8 - 5.6.21, 7.0.0 - 7.0.20, 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
&1

preferences:
201.15 ms | 404 KiB | 225 Q