title: Does render get called immediately after setState?
body: <p>I have the following function:  </p>
  
  <pre><code>onSelectDepartment = (evt) =&gt; {
      const department = evt.target.value;
      const course = null;
  
      this.setState({ department, course });
  
      this.props.onChange({ name: 'department', value: department });
      this.props.onChange({ name: 'course', value: course });
  
      if (department) this.fetch(department);
  };
  </code></pre>
  
  <p>The question is, after the <code>setState</code> function get called, the <code>render</code> function on the component will be executed immediately or after function call is finished?  </p>