Question

我有两个数组，一个包含正确答案的索引号correctAnswers

userAnswers包含用户选择的答案索引号

如何检查两者在索引上是否具有相同的值，如果是，则在Total

添加+1

    this.state = {
        correctAnswers: [], // [1, 2, 3, 1, 2, 1, 3, 3, 4, 3]
        userAnswers: [],    // [1, 3, 1, 2, 2, 1, 1, 3, 4, 3]
        Total: 0
    };

因此，在上述案例中，总计应为Total =6

我的尝试：

const correctAnswers = this.state.correctAnswers;
    const userAnswers = this.state.userAnswers;

    compareAnswers() {
    for (var i = 0; i < correctAnswers.length; i++) {
        if (correctAnswers[i] === userAnswers[i]) {
            this.setState({ Total: +1 });
        } else console.log("ITS NOT A RIGHT ANSWER ");
    }
   }

Answer 1

好的，因为它是一个对象内部的数组，而实际对象有一个this引用，我们必须适应它。

  for(var i=0;i<this.state.correctAnswers.length;i++){
  if(this.state.correctAnswers[i] === this.state.userAnswers[i]){
    this.state.Total++;
  }
}

使用此方法，我们可以动态比较两个数组。希望这有帮助！

Answer 2

您的尝试看起来很不错，只是它有语法错误（您不能这样做Total: +1）。相反，您可以使用功能setState语法，对于您的代码段，它将如下所示：

compareAnswers() {
    for (var i = 0; i < correctAnswers.length; i++) {
        if (correctAnswers[i] === userAnswers[i]) {
            this.setState(oldState => ({...oldState, Total: oldState.Total++}));
        } else console.log("ITS NOT A RIGHT ANSWER ");
    }
}

然而，批量所有总和可能更好，只在我们完成时设置状态，这看起来像：

compareAnswers() {
    let newTotal = 0;
    for (var i = 0; i < correctAnswers.length; i++) {
        if (correctAnswers[i] === userAnswers[i]) {
            newTotal++;
        } else console.log("ITS NOT A RIGHT ANSWER ");
    }

    this.setState({Total: newTotal})
}

Answer 3

我的尝试基于以下假设：所有问题都是强制性的，并且将由用户按顺序回答：

compareAnswer() {
    // Addressing the best case i.e. when all user answers are correct
    if (JSON.stringify(this.state.correctAnswers) == JSON.stringify(this.state.userAnswers)) {
           this.setState({ Total: this.state.correctAnswers.length });
    } else {
           for (var i=0; i<this.state.userAnswers.length; i++) {
               if (this.state.correctAnswers[i] === this.state.userAnswers[i]) {
                  this.setState({ Total: this.state.Total++ });
               }
           }
    }
}

Answer 4

向您已拥有的对象添加方法：

＆＃13;

let state = {
  correctAnswers: [1, 2, 3, 1, 2, 1, 3, 3, 4, 3],
  userAnswers: [1, 3, 1, 2, 2, 1, 1, 3, 4, 3],
  Total: 0,
  evalScore() {
    this.correctAnswers.forEach((answer, index) => {
        if (answer === this.userAnswers[index]) {
          this.Total++
        }
    })
  }
}

state.evalScore();
console.log(state.Total);

＆＃13;

您甚至可以使用Total属性并使其像计算属性一样工作：

＆＃13;

let state = {
  correctAnswers: [1, 2, 3, 1, 2, 1, 3, 3, 4, 3],
  userAnswers: [1, 3, 1, 2, 2, 1, 1, 3, 4, 3],
  Total() {
    // make sure both array have the same number of elements
    if(this.correctAnswers.length !== this.userAnswers.length) {
      return null;
    }
    let total = 0
    this.correctAnswers.forEach((answer, index) => {
        if (answer === this.userAnswers[index]) {
          total++
        }
    })
    return total
  }
}

console.log(state.Total());

＆＃13;

修改：Google Chrome屏幕截图

Answer 5

您可以使用forEach和三元条件：

state.Total += (c === state.correctAnswers[i] ? 1 : 0)

＆＃13;

var state = {
  correctAnswers: [1, 2, 3, 1, 2, 1, 3, 3, 4, 3],
  userAnswers: [1, 3, 1, 2, 2, 1, 1, 3, 4, 3],
  Total: 0
};

state.userAnswers.forEach((c, i) => state.Total += (c === state.correctAnswers[i] ? 1 : 0));

console.log(state)

＆＃13;

.as-console-wrapper { max-height: 100% !important; top: 0; }

＆＃13;

如何检查this.state中的两个数组是否包含相同的值？

5 个答案:

修改：Google Chrome屏幕截图