该功能没有给我正确的结果

编程问答 2022-06-06

问题描述

我正在尝试使用JavaScript构建功能，该功能将随机问题与3种可能的答案一起提示到提示中。用户给出答案，该功能在警报框中显示结果（无论答案是否正确）。恰恰在那里，我遇到了麻烦。因为无论给出的答案是正确还是错误，它总是会显示出答案是不正确的。我已经检查了100遍代码，但是找不到我的错误。有人可以帮我解释我哪里出错了吗？

此外，如果在不使用JQuery的情况下对代码进行了任何改进，我将很乐意听到它们！我是最近才开始学习JS的，所以欢迎大家输入！

// Build function constructor for the questions with inside: the question,the answers and the correct answer.
function Question(question,[answer1,answer2,answer3],correctAnswer) {
  // Add an instance to Question to count the total amount of questions.
  Question.instances++;
  // Create the blueprint for the questions
  this.theQuestion = question;
  this.theAnswer = [answer1,answer3];
  this.correctAnswer = correctAnswer;
  // Check if the answer given is correct
  this.checkAnswer = function(givenAnswer) {
    console.log(this.correctAnswer + ' ' + givenAnswer);
    if (this.correctAnswer === givenAnswer) {
      alert('Well done,that answer is correct!');
    } else {
      alert('Sorry,but that is NOT correct!');
    };
  }
}
// Set the total amount of questions to 0
Question.instances = 0;

// Create an empty array to store the questions in
var allQuestions = [];

// Create a couple questions using the Question function constructor
var q0 = new Question('What is my name?',['Herman','Peter','Sander'],0);
var q1 = new Question('How old am I?',[23,32,36],1);
var q2 = new Question('What is the name of my daugther?',['Julia','Sandra','Marijke'],1);
var q3 = new Question('What is the name of my wife?',['Esther','Marijke','Vladlena'],2);

// Push the question to the empty Array
allQuestions.push(q0);
allQuestions.push(q1);
allQuestions.push(q2);
allQuestions.push(q3);

// Create a function that generates a random question into prompt and checks if the answer is correct
function randomQuestion() {
  var randomNr = Math.floor(Math.random() * Question.instances); // Give a random number based on the amount of questions
  var question = allQuestions[randomNr].theQuestion; // Random question based on the number generated
  // Set the possible answers.
  var answer1 = allQuestions[randomNr].theAnswer[0];
  var answer2 = allQuestions[randomNr].theAnswer[1];
  var answer3 = allQuestions[randomNr].theAnswer[2];
  // var correctAnswer = allQuestions[randomNr].correctAnswer;
  // Prompt the question with the possible answers.
  var answer = prompt(question + '\n' + '0: ' + answer1 + '\n' + '1: ' + answer2 + '\n' + '2: ' + answer3);
  // Check if the answer is correct.
  allQuestions[randomNr].checkAnswer(answer)
}
<button onclick="randomQuestion()">Give me a question!</button>

解决方法

将givenAnswer转换为数字并进行比较-if (this.correctAnswer === +givenAnswer) 

// Build function constructor for the questions with inside: the question,the answers and the correct answer.
function Question(question,[answer1,answer2,answer3],correctAnswer) {
  // Add an instance to Question to count the total amount of questions.
  Question.instances++;
  // Create the blueprint for the questions
  this.theQuestion = question;
  this.theAnswer = [answer1,answer3];
  this.correctAnswer = correctAnswer;
  // Check if the answer given is correct
  this.checkAnswer = function(givenAnswer) {
    console.log(this.correctAnswer + ' ' + givenAnswer);
    if (this.correctAnswer === +givenAnswer) {
      alert('Well done,that answer is correct!');
    } else {
      alert('Sorry,but that is NOT correct!');
    };
  }
}
// Set the total amount of questions to 0
Question.instances = 0;

// Create an empty array to store the questions in
var allQuestions = [];

// Create a couple questions using the Question function constructor
var q0 = new Question('What is my name?',['Herman','Peter','Sander'],0);
var q1 = new Question('How old am I?',[23,32,36],1);
var q2 = new Question('What is the name of my daugther?',['Julia','Sandra','Marijke'],1);
var q3 = new Question('What is the name of my wife?',['Esther','Marijke','Vladlena'],2);

// Push the question to the empty Array
allQuestions.push(q0);
allQuestions.push(q1);
allQuestions.push(q2);
allQuestions.push(q3);

// Create a function that generates a random question into prompt and checks if the answer is correct
function randomQuestion() {
  var randomNr = Math.floor(Math.random() * Question.instances); // Give a random number based on the amount of questions
  var question = allQuestions[randomNr].theQuestion; // Random question based on the number generated
  // Set the possible answers.
  var answer1 = allQuestions[randomNr].theAnswer[0];
  var answer2 = allQuestions[randomNr].theAnswer[1];
  var answer3 = allQuestions[randomNr].theAnswer[2];
  // var correctAnswer = allQuestions[randomNr].correctAnswer;
  // Prompt the question with the possible answers.
  var answer = prompt(question + '\n' + '0: ' + answer1 + '\n' + '1: ' + answer2 + '\n' + '2: ' + answer3);
  // Check if the answer is correct.
  allQuestions[randomNr].checkAnswer(answer)
}
<button onclick="randomQuestion()">Give me a question!</button>

,

this.correctAnswer是索引，您正在比较该索引，而不是值。

更改：

if (this.correctAnswer === givenAnswer) {

收件人

if (this.theAnswer[this.correctAnswer] === givenAnswer) {


// Build function constructor for the questions with inside: the question,answer3];
  this.correctAnswer = correctAnswer;
  // Check if the answer given is correct
  this.checkAnswer = function(givenAnswer) {
      console.log(this.theAnswer[this.correctAnswer] + ' ' + givenAnswer);
      if (this.theAnswer[this.correctAnswer] === givenAnswer) {
          alert('Well done,that answer is correct!');
      } else {
          alert('Sorry,but that is NOT correct!');
      };
  }
}
// Set the total amount of questions to 0
Question.instances = 0;

// Create an empty array to store the questions in
var allQuestions = [];

// Create a couple questions using the Question function constructor
var q0 = new Question('What is my name?',2);

// Push the question to the empty Array
allQuestions.push(q0);
allQuestions.push(q1);
allQuestions.push(q2);
allQuestions.push(q3);

// Create a function that generates a random question into prompt and checks if the answer is correct
function randomQuestion() {
  var randomNr = Math.floor(Math.random() * Question.instances); // Give a random number based on the amount of questions
  var question = allQuestions[randomNr].theQuestion; // Random question based on the number generated
  // Set the possible answers.
  var answer1 = allQuestions[randomNr].theAnswer[0]; 
  var answer2 = allQuestions[randomNr].theAnswer[1];
  var answer3 = allQuestions[randomNr].theAnswer[2];
  // var correctAnswer = allQuestions[randomNr].correctAnswer;
  // Prompt the question with the possible answers.
  var answer = prompt(question + '\n' + '0: ' + answer1 + '\n' + '1: ' + answer2 + '\n' + '2: ' + answer3); 
  // Check if the answer is correct.
  allQuestions[randomNr].checkAnswer(answer)
}
<button onclick="randomQuestion()">Give me a question!</button>

,

比较时，将输入的内容通过Number()。检查代码段

// Build function constructor for the questions with inside: the question,answer3];
  this.correctAnswer = correctAnswer;
  // Check if the answer given is correct
  this.checkAnswer = function(givenAnswer) {
    console.log(this.correctAnswer + ' ' + givenAnswer);
    if (this.correctAnswer === +Number(givenAnswer)) {
      alert('Well done,2);

// Push the question to the empty Array
allQuestions.push(q0);
allQuestions.push(q1);
allQuestions.push(q2);
allQuestions.push(q3);

// Create a function that generates a random question into prompt and checks if the answer is correct
function randomQuestion() {
  var randomNr = Math.floor(Math.random() * Question.instances); // Give a random number based on the amount of questions
  var question = allQuestions[randomNr].theQuestion; // Random question based on the number generated
  // Set the possible answers.
  var answer1 = allQuestions[randomNr].theAnswer[0];
  var answer2 = allQuestions[randomNr].theAnswer[1];
  var answer3 = allQuestions[randomNr].theAnswer[2];
  // var correctAnswer = allQuestions[randomNr].correctAnswer;
  // Prompt the question with the possible answers.
  var answer = prompt(question + '\n' + '0: ' + answer1 + '\n' + '1: ' + answer2 + '\n' + '2: ' + answer3);
  // Check if the answer is correct.
  allQuestions[randomNr].checkAnswer(answer)
}
<button onclick="randomQuestion()">Give me a question!</button>

functionfunctionfunctionfunction-constructorif-statementjavascript