Edit in JSFiddle

// Preact code
class SomeClassName extends Component {
    constructor () {
        super();
        this.state = {
            message: ''
        };
    }
    render(props, state) {
      return (
        <div>
            <p>{state.message}</p>
        </div>
      )
    }
}

// React code
class SomeClassName extends Component {
    constructor () {
        super();
        this.state = {
            message: ''
        };
    }
    render() {
      return (
        <div>
            <p>{this.state.message}</p>
        </div>
      )
    }
}