title: The data property "article" is already declared as a prop. Use prop default value instead
body: <p>Code:</p>
  
  <pre><code>export default {
      props: {
          article: {type: Object}
      },
      data () {
          return {article: this.article}
      }, 
      methods: {
          itemClick () {
              console.log('itemClick');
          }
      }
  };
  </code></pre>
  
  <p>Vue2.1.10 warning in Chrome developers tools: <a href="https://i.stack.imgur.com/9zyf0.png" rel="noreferrer">The data property "article" is already declared as a prop. Use prop default value instead.</a></p>