Javascript 状态未在React中更新

我在YouTube上观看关于react版本16中的一个测验应用程序的教程。状态和函数中有几个变量，这些变量在

setState

的帮助下更新。未更新变量的值。更新这些变量的函数中包含以下内容。正在从

componentDidMount

函数调用此函数

displayQusetions = (questions = this.state.questions, currentQuestion, nextQuestion, previousQustion) => {
   let { currentQuestionIndex } = this.state;
   if (!isEmpty(this.state.questions)) {
      questions = this.state.questions;
      currentQuestion = questions[currentQuestionIndex];
      nextQuestion = questions[currentQuestionIndex + 1];
      previousQustion = questions[currentQuestionIndex - 1];
      const answer = currentQuestion.answer;

      this.setState({
         currentQuestion,
         nextQuestion,
         previousQustion,
         answer
      })

      console.log(this.state.currentQuestion);
      console.log(this.state.nextQuestion);
      console.log(this.state.previousQustion);
      console.log(this.state.answer);
   }
}

---

我是新来的。请提供帮助。

您可以在回调中检查状态更新值

this.setState({
                currentQuestion,
                nextQuestion,
                previousQustion,
                answer
            },()=>{
            console.log(this.state.currentQuestion);
            console.log(this.state.nextQuestion);
            console.log(this.state.previousQustion);
            console.log(this.state.answer);

})

---

这个问题几乎每天都会被问到，请搜索。React状态更新是异步的，因此在之后立即记录只会从当前渲染周期中产生状态，请使用

setState

callback参数记录新状态。这回答了你的问题吗？使用

setState

的第二个参数作为回调，该参数将在状态更新后执行。这是否回答了您的问题？