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<?php $a = 'foo'; $temporaryA = $a; $a = md5('value for finding ' . uniqid()); $variables = get_defined_vars(); $key = array_search($a, $variables); var_dump($key); $a = $temporaryA; unset ($temporaryA);
Output for 5.0.0 - 5.0.5, 5.1.0, 5.1.2 - 5.1.6, 5.2.0 - 5.2.9, 5.2.11 - 5.2.17, 5.3.0 - 5.3.4, 5.3.6 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.34, 5.6.8 - 5.6.28, 7.0.0 - 7.0.6, 7.0.20, 7.1.0 - 7.1.7, 7.2.0
string(1) "a"
Output for 5.1.1, 5.2.10, 5.3.5, 5.5.35, 7.0.14
string(4) "argc"
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9
Warning: uniqid() expects at least 1 parameter, 0 given in /in/ODK0R on line 7 string(1) "a"

preferences:
138.95 ms | 402 KiB | 174 Q