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As you write your JavaScript application, the unexpected token error always occurs because JavaScript expected a specific syntax that's not fulfilled by your current code. You can generally fix the error by removing or adding a specific JavaScript language symbol to your code.
The "Uncaught SyntaxError: Unexpected token" occurs for multiple reasons: Having a <script /> tag that points to an HTML file instead of a JS file. Getting an HTML response from a server where JSON is expected. Having a <script /> tag that points to an incorrect path.
To solve the "Uncaught SyntaxError Unexpected token 'export'" error, set the type property to module in your package. json file. Files ending with a . js extension are loaded as ES6 modules when the nearest package.
In situations where the syntax is wrong, we might encounter an Unexpected Token error. This means the parser thinks there should be another element in a particular place instead of the token the parser found.
Seeing red errors
Uncaught SyntaxError: Unexpected token <
in your Chrome developer's console tab is an indication of HTML in the response body.
What you're actually seeing is your browser's reaction to the unexpected top line <!DOCTYPE html> from the server.
Just an FYI for people who might have the same problem -- I just had to make my server send back the JSON as application/json and the default jQuery handler worked fine.
This has just happened to me, and the reason was none of the reasons above. I was using the jQuery command getJSON and adding callback=? to use JSONP (as I needed to go cross-domain), and returning the JSON code {"foo":"bar"} and getting the error.
This is because I should have included the callback data, something like jQuery17209314005577471107_1335958194322({"foo":"bar"})
Here is the PHP code I used to achieve this, which degrades if JSON (without a callback) is used:
$ret['foo'] = "bar";
finish();
function finish() {
header("content-type:application/json");
if ($_GET['callback']) {
print $_GET['callback']."(";
}
print json_encode($GLOBALS['ret']);
if ($_GET['callback']) {
print ")";
}
exit;
}
Hopefully that will help someone in the future.
I have just solved the problem. There was something causing problems with a standard Request call, so this is the code I used instead:
vote.each(function(element){
element.addEvent('submit', function(e){
e.stop();
new Request.JSON({
url : e.target.action,
onRequest : function(){
spinner.show();
},
onComplete : function(){
spinner.hide();
},
onSuccess : function(resp){
var j = resp;
if (!j) return false;
var restaurant = element.getParent('.restaurant');
restaurant.getElements('.votes')[0].set('html', j.votes + " vote(s)");
$$('#restaurants .restaurant').pop().set('html', "Total Votes: " + j.totalvotes);
buildRestaurantGraphs();
}
}).send(this);
});
});
If anyone knows why the standard Request object was giving me problems I would love to know.
I thought I'd add my issue and resolution to the list.
I was getting: Uncaught SyntaxError: Unexpected token < and the error was pointing to this line in my ajax success statement:
var total = $.parseJSON(response);
I later found that in addition to the json results, there was HTML being sent with the response because I had an error in my PHP. When you get an error in PHP you can set it to warn you with huge orange tables and those tables were what was throwing off the JSON.
I found that out by just doing a console.log(response) in order to see what was actually being sent. If it's an issue with the JSON data, just try to see if you can do a console.log or some other statement that will allow you to see what is sent and what is received.
When you request your JSON file, server returns JavaScript Content-Type header (text/javascript) instead of JSON (application/json).
According to MooTools docs:
Responses with javascript content-type will be evaluated automatically.
In result MooTools tries to evaluate your JSON as JavaScript, and when you try to evaluate such JSON:
{"votes":47,"totalvotes":90}
as JavaScript, parser treats { and } as a block scope instead of object notation. It is the same as evaluating following "code":
"votes":47,"totalvotes":90
As you can see, : is totally unexpected there.
The solution is to set correct Content-Type header for the JSON file. If you save it with .json extension, your server should do it by itself.
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