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<?php $arr[0] = 1; $arr['0'] = 2; $arr["0"] = 3; $arr[{0}] = 4; print_r($arr);
Output for 5.3.0 - 5.3.28, 5.4.0 - 5.4.28
Parse error: syntax error, unexpected '{', expecting ']' in /in/TE1tV on line 6
Process exited with code 255.

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