jQuery AJAX - Unexpected token + parsererror

问题

I wrote a script using jQuery and AJAX today, and I get some errors...

The script:

function changeAdmin(id) {
$(document).ready(function() {
    $('#ta-modarea-'+id).fadeOut('fast');
    $('#ta-m-loading-'+id).fadeIn('fast');

    $.ajax({
        type: 'POST',
        url: 'ajax_utf.php?a=changeteamadmin',
        dataType: 'json',
        data: {
            admin : $('#admin-id-'+id).val()
        },
        success: function(data) {
            $('#ta-m-loading-'+id).fadeOut('fast');
            $('#ta-modarea-'+id).text(data.msg).fadeIn('fast');
        },
        error: function(jqXHR, textStatus, errorThrown) {
            $('#ta-m-loading-'+id).fadeOut('fast');
            $('#ta-modarea-'+id).text('HTTP Error: '+errorThrown+' | Error Message: '+textStatus).fadeIn('fast');
        }
    });

    return false;
});
}

After the run, I get this error message: HTTP Error: SyntaxError: Unexpected token < | Error Message: parsererror

Could you help me, what should I do?

回答1:

You need to send an application/json header via PHP , like this:

header('Content-type: application/json');

That's because jQuery sends an Accept header (application/json, text/javascript), and this is the cause of parseerror triggered by jqXHR.

回答2:

Try

 alert( jqXHR.responseText);

in your error function

回答3:

If you have tried setting the header content type and are still getting the error. It is my expectation that the server is replying with a fault from your server side code. Usually when a debug message is given it is in pure HTML not JSON thus the unexpected token.

The quickest way to debug this is to set the DataType of the HTML instead of JSON so that you can see whatever output there is from the server, not just JSON formatted data.

Once you have seen the error that is being produced by your server side code and fixed it, you can then return to being a DataType of JSON.

回答4:

contentType: "application/json; charset=utf-8",

回答5:

Try code below, but if you receive an error like "Unexpected token <", you need to check your php file - "ajax_utf.php" and check what is returned in browser (Chrome) View->Developer->Developer Tools, Network tab -> XHR.

         $.ajax({
                type: 'post',
                url: postLink,
                dataType: 'json',
                data: postData,

            beforeSend: function (x) {
                if (x && x.overrideMimeType) {
                    x.overrideMimeType('application/json;charset=UTF-8' );
                }
            },
            success: function (result) {
                //console.log(result);
            },
            error: function (xhr, ajaxOptions, thrownError) {
                console.log(arguments);
            }
        });

回答6:

It could be an issue with missmatching PHP associative/numeric arrays and Javascript objects.

Try this:

$data = new Array();
$data['test'][] = "Row 1";
$data['test'][] = "Row 2";
echo json_encode($json, JSON_FORCE_OBJECT);

This should force json encoder to always encode to objects instead of numeric arrays and may solve the problem.

来源：https://stackoverflow.com/questions/7457044/jquery-ajax-unexpected-token-parsererror

标签

jquery

ajax

xmlhttprequest

parse-error