I keep getting Uncaught SyntaxError Unexpected token o

Question

I m trying to learn some html css javascript  so I m writing myself a teaching project   The idea was to have some vocabulary contained in a json file which would then be loaded into a table  I managed to load the file in and print out one of its values  after which I began writing the code to load the values into the table   After doing that I started getting an error  so I removed all the code I had written  leaving me with only one line  the same line that had worked before      only the error is still there   The error is as follows   Uncaught SyntaxError  Unexpected token o  anonymous function script js 10 jQuery Callbacks firejquery-1 7 js 1064 jQuery Callbacks self fireWithjquery-1 7 js 1182 donejquery-1 7 js 7454 jQuery ajaxTransport send callback   My javascript code is contained in a separate file and is simply this   function loadPageIntoDiv        document getElementById  wokabWeeks   style display    block      function loadWokab          also tried getJSON which threw the same error     jQuery get  wokab json   function data            var glacier   JSON parse data               And my JSON file just has the following right now                    english    bag            kana    kaban            kanji    K                         english    glasses            kana    megane            kanji    M            Now the error is reported in line 11 which is the var glacier   JSON parse data   line   When I remove the json file I get the error   GET http       wokab json 404  Not Found   so I know it s loading it  or at least trying to

User · Accepted Answer

Looks like jQuery takes a guess about the datatype. It does the JSON parsing even though you're not calling getJSON()-- then when you try to call JSON.parse() on an object, you're getting the error.

Further explanation can be found in Aditya Mittal's answer.

User · Answer

Simply the response is already parsed  you don t need to parse it again  if you parse it again it will give you  unexpected token o  however you have to specify datatype in your request to be of type dataType  json

User · Answer

SyntaxError  Unexpected token o in JSON   This also happens when you forget to use the await keyword for a method that returns JSON data   For example   async function returnJSONData        return     prop    2       var json str   returnJSONData    var json obj   JSON parse json str     will throw an error because of the missing await  What is actually returned is a Promise  object   not a string   To fix just add await as you re supposed to   var json str   await returnJSONData      This should be pretty obvious  but the error is called on JSON parse  so it s easy to miss if there s some distance between your await method call and the JSON parse call

User · Answer

Make sure your JSON file does not have any trailing characters before or after  Maybe an unprintable one  You may want to try this way      english   bag   kana   kaban   kanji   K     english   glasses   kana   megane   kanji   M

User · Answer

Another hints for Unexpected token errors  There are two major differences between javascript objects and json    json data must be always quoted with double quotes  keys must be quoted   Correct JSON          english    bag        kana    kaban        kanji    K      Error JSON 1          english    bag        kana    kaban        kanji    K       Error JSON 2         english   bag       kana   kaban       kanji   K      Remark  This is not a direct answer for that question  But it s an answer for Unexpected token errors  So it may be help others who stumple upon that question

User · Answer

I had a similar problem just now and my solution might help   I m using an iframe to upload and convert an xml file to json and send it back behind the scenes  and Chrome was adding some garbage to the incoming data that only would show up intermittently and cause the  Uncaught SyntaxError  Unexpected token o  error   I was accessing the iframe data like this       load-file-iframe   contents   text     which worked fine on localhost  but when I uploaded it to the server it stopped working only with some files and only when loading the files in a certain order   I don t really know what caused it  but this fixed it   I changed the line above to      load-file-iframe   contents   find  body   text     once I noticed some garbage in the HTML response     Long story short check your raw HTML response data and you might turn something up

User · Answer

Basically if the response header is text html you need to parse  and if the response header is application json it is already parsed for you   Parsed data from jquery success handler for text html response   var parsed   JSON parse data     Parsed data from jquery success handler for application json response   var parsed   data

User · Answer

The problem is very simple  jQuery get  wokab json   function data        var glacier   JSON parse data         You re parsing it twice  get uses the dataType  json   so data is already in json format  Use   ajax   dataType   json      to specifically set the returned data type

User · Answer

const getCircularReplacer        gt                  const seen   new WeakSet                  return  key  value    gt                    if  typeof value      object   amp  amp  value     null                      if  seen has value                         return                                        seen add value                                     return value                                  JSON stringify tempActivity  getCircularReplacer       Where tempActivity is fething the data which produces the error  SyntaxError  Unexpected token o in JSON at position 1 - Stack Overflow

[javascript] I keep getting "Uncaught SyntaxError: Unexpected token o"

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