php中的多条件 if ( （$page_num>=10&&$page_num=21&$page_num==31&&$page\u num=

您的代码上有=<更改如下：=10&&$page\u num=21&&$page\u num=31&&&$page\u num您的代码上有=<更改如下：=10&$page\u num=21&$page\u num=31&$page\u num这不是与

$page\u num>=10&$page\u num相同吗嗯
if
(
  ($page_num >=10 && $page_num<= 20)  || 
  ($page_num >= 21 && $page_num =< 30) || 
  ($page_num >=31 && $page_num =<40)
){
     if($i==1){
       $i = $page_num;
     }
 }

$page_num = 11;
$i=1;
if(($page_num >=10 && $page_num<= 20)  || ($page_num >= 21 && $page_num <= 30) || ($page_num >=31 && $page_num <=40)){
     if($i==1){
       $i = $page_num;
       }
 }