Codeigniter中的Ajax错误

showing this error: XHR failed to load: AJAX

This is ajax code:

     $.ajax({

           url:"<?php echo base_url();?>food/register_user/",
           type:"ajax",
           traditional:true,
           data:{data},
           dataType:"json",

           success:function(data){
             console.log(data);

           alert(data);

         },
         error: function() {

       alert("Error");
     }
   });

I think the closing braces on the error function is the problem it should look like this

$.ajax({
    url: "<?php echo base_url();?>food/register_user/",
    type: "ajax",
    traditional: true,
    data: {
        data
    },
    dataType: "json",
    success: function(data) {
        console.log(data);
        alert(data);
    },
    error: function() {
        alert("Error");
    }

});

Try this

$.ajax({
       url:"<?php echo base_url();?>food/register_user/",
       type:"post",
       traditional:true,
       data:{data},
       dataType:"json",

       success:function(data){
         console.log(data);

       alert(data);

     },
     error: function() {

   alert("Error");
 } });