Ajax从PHP函数中获取错误或成功消息

Question

I'm post data to a php function using JSON post. I want to receive two different type of responses, success and error. For example, the following function:

function some_function(){

    if ($error){
        echo "some error";
        exit;
    } else {    
        echo "everything is ok"
        exit;
    }

}

In this case, both messages will be returned as success. How can I make the error message return to the error function in the ajax? Here's the ajax code:

jQuery.ajax({

    url: '<?php echo $url; ?>',
    data: response,
    dataType: 'JSON',
    type: 'POST',
    success:function(data){
        console.log(data);
    },
    error: function(data, errorThrown){
        console.log(errorThrown);
    }

});

Answer 1

Try this one:

jQuery.ajax({

    url: '<?php echo $url; ?>',
    data: response,
    dataType: 'JSON',
    type: 'POST',
    success:function(data){
        if(data['error']){
           alert(data['error']);
          }else{
             alert(data['success']);
          }
    },
    error: function(data, errorThrown){
        console.log(errorThrown);
    }

});

On PHP page:

function some_function(){

        if ($error){
            $msg = array("error"=>"some error";
        } else {    
            $msg = array("success"=>"everything is ok");
        }
       echo json_encode($msg);die;
    }