return json from javascript function issue

Question

i am tring to return custom json object from javascript function my code is as below

html

<input type='checkbox' name='chk[]' value='1'>1
<input type='checkbox' name='chk[]' value='2'>2
<input type='text' id='txt' value='' />
<input id='btn' type='button' value='click' />

js

var json = {};

$('#btn').click(function(){
  console.log(getdata());
});
function getdata(){
  $('input:checked').each(function(i){
      json.chk = $(this).val();
      //json.chk.push({"val": $(this).val()}); gives error Uncaught TypeError: Cannot call method 'push' of undefined
  });

  json.txt = document.getElementById("txt").value;

 return json;
}

i need result like below

{
  chk: [{val: 1}, {val: 2}],
  txt: 'test'
};

i have also refered this question' answer to add item http://stackoverflow.com/questions/4538269/adding-removing-items-from-json-data-with-jquery — Pragnesh Chauhan, Nov 08 '12 at 06:03

score 6 · Accepted Answer · answered Nov 08 '12 at 06:06

6

You need to define the chk varible in the json object. Since chk is undefined, it doesn't know that it's an array.

var json = {};

$('#btn').click(function(){
    console.log(getdata());
});
function getdata(){

    json.chk = [];
    $('input:checked').each(function(i){
        json.chk.push({ val : $(this).val()});
    });

    json.txt = document.getElementById("txt").value;

    return json;
}

answered Nov 08 '12 at 06:06

Varun Achar

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it returns something like this `{chk: [ {0:[val : 1]}, {1:[val : 2]}] , txt: 'test'};` – Pragnesh Chauhan Nov 08 '12 at 06:17
the 0 and 1 are the indices of the array. they are not part of the object inside the array. The output is exactly what you mentioned in your question. If you want to check, iterate the array and print out the values, you wont see the 0 and 1 – Varun Achar Nov 08 '12 at 06:26

score 2 · Answer 2 · answered Nov 09 '12 at 05:00

chk is not define as array you need to first define as an array then push value into array.

var json = {};

    $('#btn').click(function(){
      console.log(getdata());
    });
    function getdata(){
      $('input:checked').each(function(i){
         if(json.chk)
        {
            json.chk.push({val:$(this).val()})
        }
        else
        {
            json.chk=[];
            json.chk.push({val:$(this).val()})
        }
      });

      json.txt = document.getElementById("txt").value;

     return json;
    }

return json from javascript function issue

2 Answers2