how can i return errors from php using ajax

[mahenda]

//my php code sample
<?php
include_once('con.php');
if(isset($_POST['username'])){
    $message = [];
    if(empty($_POST['username'])){
        $message['username'] = 'username required';
    }
	#some validation continue...
    $data = $_POST['username'];
    if (count($errors) === 0){
 		#ccode...
		$message['username'] = 'success your name saved';
    }
}
?>
//my jquery ajax
 $('.username').click(function() {
        $.ajax({
            url: 'user.php',
            method: 'POST',
            data: $('.user').serialize(),
            success: function(data) {
                 swal('Wow!','success message from php','success');
            },
            error: function(data) {
                 swal('Oops!','error message from php','error');
            }
        });
        return false;
    });

 

[requinix]

jQuery will consider it an error if the request responds with a 4xx or 5xx status. You can use http_response_code to set it.

Suggested status codes are:
- 400 if the request didn't have the fields you need
- 400 if the new username was invalid
- 403 if the user tried to update the status of someone they're not supposed to

jQuery won't deserialize the JSON for an error response so your code should attempt to do that itself. Then it can look for an error message.