title: ReactJS Functional Component vs Component Functions for conditional rendering
body: <p>Sometimes I want to move my conditional rendering out of <code>render()</code>, and I always have dilemma between these two approaches:</p>
  
  <pre><code>class MyComponent extends React.Component {
    _renderSomething() =&gt; {
      const {x, y, z} = this.props
      // conditional rendering based on props
    }
  
    render() {
      return (
        { this._renderSomething }
        // vs
        { renderSomething(this.props) }
        // which one is better?
      )
    }
  }
  
  const renderSomething = (props) =&gt; {
      const {x, y, z} = props
      // conditional rendering based on props
  }
  
  export default MyComponent
  </code></pre>
  
  <p>Any performance difference between <code>_renderSomething</code> and <code>this.renderSomething</code>? </p>
  
  <p>When should I use which?</p>