Initialize state in ES6 classes outside of constructor

App.js

import React, { Component } from 'react';

class App2 extends Component {

    state = {
        message: 'world'
    }
    render() {
        return (
            <h1>Hello {this.state.message} in ES6 classes outside of constuctor</h1>
        );
    }
}

export default App2;