title: How to update nested state properties in React
body: <p>I'm trying to organize my state by using nested property like this:</p>
  
  <pre><code>this.state = {
     someProperty: {
        flag:true
     }
  }
  </code></pre>
  
  <p>But updating state like this,</p>
  
  <pre><code>this.setState({ someProperty.flag: false });
  </code></pre>
  
  <p>doesn't work. How can this be done correctly?</p>