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<?php $a = 'a/b/c'; $c = substr_count($a, '/'); $d = ('[' . str_replace('/', ':[', $a) .':['.str_repeat(']', $c+1)); var_dump($d);
Output for 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 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
string(13) "[a:[b:[c:[]]]"

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