title: setState in componentWillMount doesn't reflect in componentWillMount
body: <p>I am making an ajax request In my componentWillMount function of react component. I have a state variable. I set the state of this variable as the response of the ajax call. </p>
  
  <pre><code>this.setState({state_variable: response})
  </code></pre>
  
  <p>Now in my componentDidMount function I am trying to console.log the value of state_variable. Ideally I should get the value of state_variable as what I have set above as response. But in console I see value printed as empty array which was the initialized value of state_variable. </p>
  
  <p>Why componentDidMount now able to get the value I set? What am I doing wrong</p>