php简单的数组递归

$arr = array(
    'aa' =>  array(
        'bb' => array(
            'id'=>5,
            'grade'=>5
        ),
        'cc' =>  array(
            "name"=>'some'
        ),
        'dd' =>  array(
            'ctime'=>1001
        )
    ),
    'ee' =>  array(
        'ff' =>array(
            'age'=> 25,
            'sex'=>1
        )
    )
);

  function a($arr){
    if(!is_array($arr)){
            echo $arr."\n";
        }else
            foreach($arr as $k=>$v){
                if(is_array($v)){
                    echo "键是$k"."\n";
                    echo a($v)."\n";
        }else{
            echo "键是$k"."\n";
            echo $v."\n";
        }
    }
}
a($arr);

结果
键是aa
键是bb
键是id
5
键是grade
5

键是cc
键是name
some

键是dd
键是ctime
1001

键是ee
键是ff
键是age
25
键是sex
1