title: how to add key value pair in the JSON object already declared
body: <p>I have declared a JSON Object and added some key value pair in that like:</p>
  
  <pre><code>var obj  = {};
  </code></pre>
  
  <p>and added some data into it like:</p>
  
  <pre><code>obj = {
  "1":"aa",
  "2":"bb"
  };
  </code></pre>
  
  <p>But I want to add more key value pair in the same object, if I add key value pair same above mentioned then it replace the old one. So could any one please tell me how I can append data in the same JSON Object i.e. obj.</p>