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<?php $input = ["a", "b"]; function search($input) { $result = $input; foreach($input as $a) foreach($input as $b) $result []= $a . $b; array_walk($result, null); return array_unique($result); } echo json_encode(search($input));
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
Fatal error: Uncaught TypeError: array_walk(): Argument #2 ($callback) must be a valid callback, no array or string given in /in/1SKcf:12 Stack trace: #0 /in/1SKcf(12): array_walk(Array, NULL) #1 /in/1SKcf(16): search(Array) #2 {main} thrown in /in/1SKcf on line 12
Process exited with code 255.
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.37, 5.6.0 - 5.6.28, 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
Warning: array_walk() expects parameter 2 to be a valid callback, no array or string given in /in/1SKcf on line 12 ["a","b","aa","ab","ba","bb"]
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/1SKcf on line 3
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/1SKcf on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/1SKcf on line 3
Process exited with code 255.

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