考虑以下数组$details=array(array('lname'=>'A','fname'=>'P','membkey'=>700,'head'=>'y'),array('lname'=>'B','fname'=>'Q','membkey'=>540,'head'=>'n'),array('lname'=>'C','fname'=>'R','membkey'=>700,'head'=>'n'),array('lname'=>'D','fname'=>'S','membkey'=>540,'head'=>'y'),array('lname'=>'E','fname'=>'T','me