AJAX detect entered username without refreshing

This time I will bring you AJAX to detect the entered user name without refreshing. What are the precautions for AJAX to detect the entered user name without refreshing? The following is a practical case. Let’s take a look. Let’s take a look at the schematic diagram first

register.php

 
  
  
  
 

 
  

   
   

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registerPro1.php

网名不可用";
// }else{
//  $info.="网名可用";
// }
// echo $info;
 //③
// $info="";
// if($username=="abc"){
//  //这里的$info返回的是一个字串
//  $info.='{"res":"不可用","id":"123","age":"5"}';
// }else{
//  $info.='{"res":"可用","id":"3","age":"1"}';
// }
// echo $info;
 //③+
 $info="";
 if($username=="abc"){
  //这里的$info返回的是一个字串
  $info.='[{"res":"不可用","id":"123","age":"5"},{"res":"abc不可用","id":"3","age":"0"}]';
 }else{
  $info.='[{"res":"可用","id":"1","age":"15"},{"res":"可用","id":"83","age":"9"}]';
 }
 echo $info;
?>

Rendering:

# I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

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