22

I know this question has been asked many times but I can't find similarity with my issue. I'm getting this error only in Chrome, in every other browser everything is ok. I return data with JSON in several places but since my code works in other browsers I assume nothing is wrong with it. Chrome doesn't show me where is error (in my code) it shows me these errors:

enter image description here

This is how I use JSON:

$.post("getData.php", {'id' : id}, function(data){
        var obj = jQuery.parseJSON(data);
.
.
.

... some mysqli query
$data = $query->fetch_assoc();
echo json_encode($data);

So I don't see a problem here, can someone help me with this.

Improve this question
6
  • What's the status code, 200 OK? If not, you might be getting the html for the error response and it will not parse and generate that kind of error. Probably something with your SQL query. Commented Oct 24, 2013 at 21:19
  • Everything is 200 OK, and in some places I get 200 Found. As I said, it works perfectly in Firefox, I don't see a reason why would I get some error if it works in Firefox Commented Oct 24, 2013 at 21:49
  • Have you tried to turn off AdBlock and test it? Commented Oct 24, 2013 at 22:09
  • @Mario Yes, I tried, but it's the same Commented Oct 25, 2013 at 6:01
  • Possible duplicate of Error: Uncaught SyntaxError: Unexpected token < Commented Jun 20, 2017 at 22:25

15 Answers 15

Reset to default
17

You can check your Network (console) and See the answer from the Server ... The "<" will be the first letter of your response. Something like "<"undefined index XY in line Z>"

Improve this answer
Sign up to request clarification or add additional context in comments.

3 Comments

Can you provide an live example?
I'm sorry but I can't. I noticed it gives me error for first < sign. So currently first < sign is in <!DOCTYPE html>, if I delete < then it gives me same error but instead < it says ! is unexpected token.
No... If you recieve a response from the Server which jquery can't parse you will See uncought errors like that... .. Many Seen errors also "o" or "u" and this letter is the first sign of the response jquery cant parse....
8

My solution to this is pretty unbelievable.

<script type="text/javascript" src="/js/dataLayer.js?v=1"></script>

The filename in the src attribute needed to be lowercase:

<script type="text/javascript" src="/js/datalayer.js?v=1"></script>

and that somewhat inexplicably fixed the problem.

In both cases the reference was returning 404 for testing.

Improve this answer

2 Comments

I had the same problem so changed the file name into another name and it worked. My file name did not have capital letter anywhere.
This fixed it for me. The strange thing is that it was working with a capital letter for quite some time - then all of a sudden threw the error.
7

Error with Uncaught SyntaxError: Unexpected token < using @Mario answer but that was only part of my problem. Another problem is, javascript doesn't get any data from PHP file. That was solved using this code, inside PHP file: header("Content-Type: text/javascript; charset=utf-8"); This answer is found on this link, where I opened another question to solve this issue: Can't receive json data from PHP in Chrome and Opera

Improve this answer

2 Comments

I had this problem twice so far. The first time the solution was to replace all the echos in the .php file into 1 array with different entries. The second time (just now), it was simpler: I had to delete the comment in top of my .php file ( The file started like this: <!-- comment... --> <?php....?>). So this is where the < was coming from.
It still doesn't work for me. What was Mario's answer, I can't find it.
4

I got the same error ("Uncaught SyntaxError: Unexpected token <" ) at these two lines when testing a sample application . 

<script type = "text/javascript"  src="raphael-min.js"></script>
<script type = "text/javascript"  src="kuma-gauge.jquery.js"></script>

After a control, I realized that, local file locations are not correct and my local server app returns default page as the result. Client app can find the files but the founded files are default page, not the *.js files. So I receive Uncaught SyntaxError: Unexpected token <

I changed to orginal location on the intenet andit solved.

<script type = "text/javascript"  src="//cdnjs.cloudflare.com/ajax/libs/raphael/2.1.2/raphael-min.js"></script>
<script type = "text/javascript"  src="//www.jqueryscript.net/demo/Creating-Animated-Gauges-Using-jQuery-Raphael-js-kumaGauge/js/kuma-gauge.jquery.js"></script>
Improve this answer

1 Comment

This happened to me when my scripts were in the subdirectory stuff/scripts but I went to the URL stuff/whatever/ instead of stuff/whatever. Because stuff/whatever/scripts didn't exist.
2

To override the error that you might experience in Chrome (and probably in Safari), try to set the Ajax parameter as dataType: "json". Then you shouldn't call parseJSON() on the obj because the response you'll get comes deserialized.

Improve this answer

2 Comments

I don't see this error anymore but I don't receive any data from server, although this same code works in Firefox: pastebin.com/md2GC4CA
What kind of data are you expecting from the ajax response - html, JSON?
1

I have commented my this code : // $('#description').val('<?php echo $_POST['description']; ?>'); and I got that error.

Improve this answer

Comments

1 
header("Location: route_to_main_page");

I've encountered this problem while having a custom 404 error handling file. Instead of throwing some html content it was suppose to redirect to the main page url. It worked well.

Then I used this as a skeleton for a next project, therefore not changing the "route_to_main_page" actually on the new project (different URL) became a "route_to_external_url" so any 404 errors within your code (missing css stylesheets, js libraries) would return the "Uncaught SyntaxError: Unexpected token <".

Improve this answer

Comments

1

I faced similar issue when I moved some of the js files into folders then deployed into production, after some struggle I found out that the js files were not actually got deployed to production. So

  1. make sure that the file for which the error is shown does exist in the server
  2. the path given is correct

So, In the absence of js file, the server then server responds with as below 

<!doctype html>
    <html>
        <someTag />
        <AnotherTag />
    </html>

Thats why we get Uncaught SyntaxError: Unexpected token <

Improve this answer

Comments

1

It could be that the resource you're trying to request is under restricted access via your web app configuration, i.e. user must be logged for the application to serve the file.

Try adding this to your Web.Config file (this is for .NET applications):

<location path="js/resourcefile.js">
  <system.web>
    <authorization>
      <allow users="?" />
    </authorization>
  </system.web>
</location>

You can place it anywhere before the closing configuration tag.

Improve this answer

Comments

0

If you are trying to perform Ajax file upload or something similar, you have to get rid of displaying further HTML after printing your ajax response text. Probably that gives this error message. If you are using PHP framework you have to follow framework syntax to end the application. If you are coding pure PHP, you can use 'exit' after your ajax response text.

Hope this will help save some ones' time on finding solution for this. :) happy coding!!!

Improve this answer

Comments

0

change it to 

$.post({ 
         url = 'getData.php',  
         data : { 'id' id } , 
         dataType : 'text'
       });

This way ajax will not try to parse the data into json or similar

Improve this answer

Comments

0

Seems everyone has difference experiences from this and therfore solutions as well :) This is my "story".

My thing came from a validate.php file fetched with ajax. The output was meant to be : 

$response['status'] = $status;
$response['message'] = $message;
$response['param'] = $param;

echo json_encode($response);

And the error that cause the "Unexpected token <" error was simply that in some cases $message hadn't been declared (but only $status and $param). So, added this in the beginning of the code.

$message = ''; // Default value, in case it doesn't get set later on.

So I guess, those "little things" may in this scenario big of quite importance. So be sure to really check your code and making it bulletproof.

Improve this answer

Comments

0

Had the same error. My problem was caused from shifting around my project directory, and failing to adjust the path to my static files on the server to reflect the new path (i.e. was ./src/public but should have been ./public).

Improve this answer

Comments

0

The only place it worked for me is when I place the scripts in public folder where my index.html resides and then placing these <script type="text/javascript" src="test/test.js"></script> inside <body> tag.

Improve this answer

Comments

0

In my case, host had enabled iisnode at my web.config file so I've commented.

<?xml version="1.0" encoding="UTF-8"?>
 <configuration>
   <system.webServer>
    <handlers>
        <!-- <add name="iisnode" path="*.js" verb="*" modules="iisnode" /> -->
    </handlers>
  </system.webServer>
 </configuration>
Improve this answer

Comments

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.