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<?php $array[0]['d'] = 'd1'; $array[0]['a'] = 'a1'; $array[1]['d'] = 'd2'; $array[1]['a'] = 'a2'; $array[2]['d'] = 'd3'; $array[2]['a'] = 'a3'; $array[3]['d'] = 'd1'; $array[3]['a'] = 'a1'; print_r($array); $keys = array_keys($array,"a1"); print_r($keys); ?>

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