title: Checkbox checked in React.js
body: <p>I'm trying to use the javascript function .checked() in React.js like this : </p>
  
  <pre><code>componentDidMount () {
      document.getElementById("myCheck").checked = true;
  }
  </code></pre>
  
  <p>But I have an error in my console : "la propriété 'checked' n'existe pas sur le type HTMLlement" </p>
  
  <p>How can I use this in React.js ? </p>
  
  <p>Thank you</p>