请问以下两种写法 哪种执行效率高呢？

-------------------------------

foreach ($arr as $k => $i){
list($value) = each($arr);
echo '

'.$value.'

';
echo'';
foreach ($i as $item => $kitem) {
echo '';
while(list($key,$value) = each($kitem)){
echo '' ;
}
echo '';
}
echo '

'.$value.'

';
};

-----------------------------------------------------------

while(list($key,$value)=each($arr)){

echo "

" . $key . "

";

echo "";

while(list($k,$v)=each($value)){

echo '';

while(list($kk,$vv)=each($v)){

echo '';

}

echo '';

}

echo '

' . $vv . '

';

}