为什么我不能使用jQuery.parseJSON（json）解析json字符串？

Question

I am trying to parse a response of a string which is a json string. In another page of my web app following code is working fine. but its not working for my current page i am working with. Following is the code:

 $.ajax({
    type: 'POST',
    url: 'http://mywebapp.com/sendnames',
    data: {},
    success: function(result) {
        alert('result: '+result);
        var obj = jQuery.parseJSON(result);
        alert('obj: '+obj);

    // doing rest of stuff  
    }

});

first alert comes and shows right result. result is:

 [
   "Richard",
   "Eric",
   "John"
 ]

but second alert does not come. i checked it, its a valid json. why can not i parse this json with jQuery.parseJSON(). Thanks in advance.

Answer 1

Try to add return type: dataType : json

$.ajax({
        type: 'POST',
        url: 'http://mywebapp.com/sendnames',
        data: {},
        dataType:'json',
        success: function(result) {
          console.log('result: '+result);        
        // doing rest of stuff  
        }

    });

"json":
Evaluates the response as JSON and returns a JavaScript object. In jQuery 1.4 the JSON data is parsed in a strict manner; any malformed JSON is rejected and a parse error is thrown. (See json.org for more information on proper JSON formatting.) "jsonp": Loads in a JSON block using JSONP. Adds an extra "?callback=?" to the end of your URL to specify the callback. Disables caching by appending a query string parameter, "_=[TIMESTAMP]", to the URL unless the cache option is set to true. http://api.jquery.com/jQuery.ajax/

Answer 2

Replace $.ajax by $.getJSON . This is guaranteed to trigger $.parseJSON internally, so result will already be the desired JS object.

$.getJSON({
   type: 'POST',
   url: 'http://mywebapp.com/sendnames',
   data: {},
   success: function(obj) {
      alert('obj: '+obj);
      // doing rest of stuff  
   }
});

Answer 3

Try with adding dataType:'text' , it will return string as result. and your code will run as you expect.

Answer 4

See the accepted answer here

You're parsing an object. You parse strings, not objects; jQuery.parseJSON only takes strings.

Because $.ajax already parsed the data, result is Javascript object not a string. parseJSON expects a string parameter.

FROM DOCS (more on .ajax() data types here ):

The json type parses the fetched data file as a JavaScript object and returns the constructed object as the result data. To do so, it uses jQuery.parseJSON() when the browser supports it; otherwise it uses a Function constructor

.