如何对有push方法的数组进行setState？

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      array: [1, 2, 3]
    };
  }

  handlePush = () => {
    const newArray = [...this.state.array]; // 拷贝原数组
    newArray.push(4); // 对拷贝的数组进行操作
    this.setState({ array: newArray }); // 更新状态
  }

  render() {
    return (
      <div>
        <button onClick={this.handlePush}>Push</button>
        <ul>
          {this.state.array.map(item => <li key={item}>{item}</li>)}
        </ul>
      </div>
    );
  }
}