JSON Parse Uncaught SyntaxError Unexpected token o

Question

I am having trouble with JSON returned from a web service  It looks like the JSON lacks quotes  but when I add quotes to the JSON  I get an error  Here is the error message   Uncaught SyntaxError  Unexpected token o  When I log the string to console  object Object   object Object    Here is some example code that simulates the error     Error I am trying to solve var jsonString       Id   10   Name   Matt     Id   1   Name   Rock      var myData   JSON parse jsonString      document  ready function         var  grouplist       groups          each myData  function                 lt li gt     this Name     lt  li gt    appendTo  grouplist                 Here is the same code with the single quotes around the string  It works    Successful Javascript var jsonString       Id   10   Name   Matt     Id   1   Name   Rock      var myData   JSON parse jsonString      document  ready function         var  grouplist       groups          each myData  function                 lt li gt     this Name     lt  li gt    appendTo  grouplist                  Successful HTML  lt ul id  groups  gt  lt  ul gt    But when I try to add quotes to the string  like I seem to need to in my real code  it fails     Does not work when I need to append quotes to the string  var jsonStringNoQuotes      Id   10   Name   Matt     Id   1   Name   Rock     jsonStringQuotes         jsonStringNoQuotes        var myData   JSON parse jsonStringQuotes      document  ready function         var  grouplist       groups          each myData  function                 lt li gt     this Name          this Id     lt  li gt    appendTo  grouplist                 Here is the error  log string to console  object Object   object Object   data js 809 Uncaught SyntaxError  Unexpected token    I m stumped  Any help appreciated  Thank you

User · Answer

Your last example is invalid JSON  Single quotes are not allowed in JSON except inside strings  In the second example  the single quotes are not in the string  but serve to show the start and end   See http   www json org  for the specifications   Should add  Why do you think this   like I seem to need to in my real code   Then maybe we can help you come up with the solution

User · Answer

Maybe what comes from the server is already evaluated as JSON object  For example  using jQuery get method     get   service   function data        var obj   data                       obj  is evaluated at this point if server responded           with  application json  or similar                  for  var i   0  i  lt  obj length  i              console log obj i  Name                     Alternatively  if you need to turn JSON object into JSON string literal  you can use JSON stringify   var json      Id   10   Name   Matt     Id   1   Name   Rock     var jsonString   JSON stringify json     But in this case I don t understand why you can t just take the json variable and refer to it instead of stringifying and parsing

User · Answer

var jsonStringNoQuotes      Id   10   Name   Matt     Id   1   Name   Rock       it  will create json object  no need to parse   jsonStringQuotes         jsonStringNoQuotes          will return    object    thats why it below  is causing error   var myData   JSON parse jsonStringQuotes

User · Answer

Without single quotes around it  you are creating an array with two objects inside of it  This is JavaScript s own syntax  When you add the quotes  that object  array 2 objects  is now a string   You can use JSON parse to convert a string into a JavaScript object  You cannot use JSON parse to convert a JavaScript object into a JavaScript object     String - you can use JSON parse on it var jsonStringNoQuotes       Id   10   Name   Matt     Id   1   Name   Rock         Already a javascript object - you cannot use JSON parse on it var jsonStringNoQuotes      Id   10   Name   Matt     Id   1   Name   Rock       Furthermore  your last example fails because you are adding literal single quote characters to the JSON string  This is illegal  JSON specification states that only double quotes are allowed  If you were to console log the following     console log        Id   10   Name   Matt     Id   1   Name   Rock            Logs    object Object   object Object     You would see that it returns the string representation of the array  which gets converted to a comma separated list  and each list item would be the string representation of an object  which is  object Object   Remember  associative arrays in javascript are simply objects with each key value pair being a property value   Why does this happen  Because you are starting with a string      then you are trying to append the array to it  which requests the string representation of it  then you are appending another string       Please do not confuse JSON with Javascript  as they are entirely different things  JSON is a data format that is humanly readable  and was intended to match the syntax used when creating javascript objects  JSON is a string  Javascript objects are not  and therefor when declared in code are not surrounded in quotes   See this fiddle  http   jsfiddle net NrnK5

[javascript] JSON.Parse,'Uncaught SyntaxError: Unexpected token o

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