如何更新数组Reactjs中的值

Question

我有一个固定的数组(9)，我想更新数组的值，这很好用，但我想优化代码：

​

constructor (props) {
  super();
  this.state ={
    token: "X",
    val: ["","","","","","","","",""]
  };
}

intelligentComputerPlay () {
  this.setState({
    val: [
      this.state.token,
      this.state.val[1],
      this.state.val[2],
      this.state.val[3],
      this.state.val[4],
      this.state.val[5],  
      this.state.val[6],  
      this.state.val[7],  
      this.state.val[8]
    ];
  });

​

Answer 1

我想这能行得通。

this.setState(prevState => ({
     val: [token, ...prevState.val.slice(1, prevState.val.length - 1)]
}));