如果{}，则使用isset的有效方法

Question

I was wondering: I use this code:

if($_GET['rvr_filter_select'] == $qRows) {
    $sSelected = 'selected';    
}

But in this case when php doesnt get rvr_filter_select it gives a error of a undifined index rvr_filter select

Now I was wondering of this is a valid way to solve this problem. It doesnt output the error anymore but I dont know if it will work the same as the code above:

if(isset($_GET['rvr_filter_select']) == $qRows) {
    $sSelected = 'selected';    
}

Answer 1

You should use

if(isset($_GET['rvr_filter_select']) && $_GET['rvr_filter_select'] == $qRows) 

The isset function returns a boolean: true or false.