未捕获的SyntaxError：意外的令牌＆＃39;在位置0的JSON中

Question

我无法理解单引号来自json格式。

这是ajax

$().ready(function() {
    $("form#saveForm").validate({
        debug: true,
        onkeyup: false,
        submitHandler: function(form) {
            var form = new FormData($("#saveForm")[0]);
            console.log(form);
            $.ajax({
                type: "post",
                url: "<?php echo base_url('admin_seo_controller/assignDomainToUser/'); ?>",
                data: new FormData($("#saveForm")[0]),
                contentType: false,
                processData: false,
                success: function(data) {
                    console.log(data);
                    jdata = $.parseJSON(data);
                    console.log(jdata);
                    if (jdata.status_code == 200) {
                        $("#d_conf_msg").empty().html("<p>Success!</p>").dialog('open');
                    } else {
                        $("#d_notif_msg").empty().html("<p>" + jdata.status_desc + "</p>").dialog('open');
                    }
                }
            });
        },
        rules: {
            file: {
                required: true
            }
        },
        messages: {
            file: "This is field is required!"
        }
    });

});

这是输出

的json格式

'{"status_code":200,"status_desc":"Success!"}

错误是

Uncaught SyntaxError: Unexpected token ' in JSON at position 0
 at Function.parse [as parseJSON] (<anonymous>)

这是我试图编码的json的数据

$response = array(
            'status_code' => 200,
            'status_desc' => 'Success!'
            );

希望有人可以帮助我。