title: Get JSON attribute value by paasing attribute name via "var" in Javascript
body: <p>In json can we get  attribute value by passing variably value . Means</p>
  
  <p>It works for me  when "name" attribute exists in my "returnData" json object </p>
  
  <pre><code>              // It works 
                 var getColValue= returnedData[0].name
  </code></pre>
  
  <p>but it give undefined error</p>
  
  <pre><code>              // It Not works 
                 var refVar ="name";
                 var getColValue= returnedData[0].refVar;
  </code></pre>