title: how to get the key of a selected value from a dropdown in reactjs?
body: <p>how to bind a json data which has a key-value pair to select html in reactjs, such that It should display the value in the drop-down and If I choose a value , I should provide the relevant key? </p>
  
  <p>For example:</p>
  
  <pre><code>var optionsdata = [
     {key='101',value='Lion'},
     {key='102',value='Giraffe'},
     {key='103',value='Zebra'},
     {key='104',value='Hippo'},
     {key='105',value='Penguin'}
    ];
  </code></pre>
  
  <p>in the drop-down, it should show "Lion","Giraffe","Zebra",...
  if I choose, Zebra, I should get the select value (Zebra) as well as the key (103, in the above example)</p>