Confused on jquery .ajax .done() function

Question

I\'m a bit confused on how to use the ajax .done() function. I\'m working on validating a form to check if a user exists in database and though ajax would be the best approach (

Answer 1

I think it should be result == 'true' as the result is a data string

I just checked, I am correct, the quotes make it work

PHP:

Javascript

username='sambob';

$(".check").blur(function(){
  $.post("validateUser.php", { username: username })
  .done(function(data) {
     if (data == 'true'){
        alert("User exists");
     }else{
        alert("User doesn't exist"); 
     }
  });
});

json PHP

json Javascript

$(".check").blur(function(){
   $.post("validateUser.php", { username : username },
   function(user){
      if (user.exists == true){
         alert("User exists");
      }else{
         alert("User doesn't exist");
      }
   }, "json");
});