这两句有什么不同？
$arr=$db->getRows("select * from pinglun ");
这两个有啥区别？
foreach($arr as $k=>$v){
foreach($arr as $v){
我看到输出是一样的啊
为什么要加一个=>
回复讨论(解决方案)
两句是一样的只是
foreach($arr as $k=>$v){
可以用$k读出数组下标
foreach($arr as $v){
这句没有
如果你只关心值，一样
如果你还关心key，就不一样了，很多时候我们对特写key的值需要单独处理就需要使用$k=>$v
如果你不用$k，那么就是一样的了。
过程一样 区别在于你是否需要取得数组的key
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