​

const update = React.addons.update;

​

class List extends React.Component {

  constructor(props) {

    super(props);

    this.state = {

      array: []

    }

    setTimeout(this.addSome, 500);

  }

  addSome = () => {

      this.setState(

        update(this.state, {array: {$push: ["First"]}}));

      this.setState(

        update(this.state, {array: {$push: ["Second"]}}));

      this.setState(

        update(this.state, {array: {$push: ["Third"]}}));

    };

​

  addSomeFixed = () => {

      this.setState( (state) => 

        update(state, {array: {$push: ["F"]}}));

      this.setState( (state) => 

        update(state, {array: {$push: ["S"]}}));

      this.setState( (state) => 

        update(state, {array: {$push: ["T"]}}));

    };

​

​

​

  render() {

​

    const list = this.state.array.map((item, i) => {

      return <li key={i}>{item}</li>

    });

       console.log(this.state);

​

    return (

      <div className='list'>

        <button onClick={this.addSome}>add three</button>

        <button onClick={this.addSomeFixed}>add three (fixed)</button>

        <ul>

        {list}

        </ul>

      </div>

    );

  }

};

​

​

ReactDOM.render(<List />, document.getElementById('app'));

​