所以我正在编写一个测验程序，其中包含一些不确定的问题（在Java中），我在完成以下事情时遇到了问题：
1）从文件加载测验问题并存储在arraylist中并访问它（需要帮助！） 2）不接受正确答案 - 给我错误（逻辑错误） 3）并非显示所有答案选择
以下是代码：
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
public class Quiz {
public void writeFile() {
Question qn = new Question();
try {
PrintWriter out = new PrintWriter("quiz.txt");
out.println(qn.Question);
out.println(qn.numberOfChoices);
qn.answerChoices = new String[qn.numberOfChoices];
for (int i = 0; i < qn.numberOfChoices; i++) {
out.println(qn.answerChoices[i]);
}
out.println(qn.correctAnswer);
out.println(qn.numOfTries);
out.println(qn.numOfCorrectTries);
out.close();
} catch (IOException f) {
System.out.println("Error.");
}
qn.getQuestion();
}
public void readFile() {
File file = new File ("quiz.txt");
boolean exists = file.exists();
Quiz q = new Quiz();
Question a = new Question();
List<String> question = new ArrayList<String>();
String[] answerChoices = a.answerChoices;
try {
if (exists == true) {
Scanner s = new Scanner(file);
a.Question = s.nextLine();
a.numberOfChoices = s.nextInt();
a.answerChoices = new String[a.numberOfChoices];
for (int i = 0; i < a.numberOfChoices; i++) {
a.answerChoices[i] = s.nextLine();
}
s.nextLine();
a.correctAnswer = s.nextInt();
a.numOfTries = s.nextInt();
a.numOfCorrectTries = s.nextInt();
a.getQuestion();
} else {
q.writeFile();
}
} catch (IOException e) {
System.out.println("File not found.");
}
}
public static void main (String[] args) {
Scanner in = new Scanner(System.in);
Quiz qz = new Quiz();
Question b = new Question();
int Selection;
List<String> question = new ArrayList<String>();
System.out.println("Welcome to the Quiz Program! Good luck!");
do {
qz.readFile();
System.out.println("Your answer?: ");
Selection = in.nextInt();
if (Selection == b.correctAnswer) {
b.numOfCorrectTries++;
b.getQuestion();
} else {
b.getQuestion();
}
} while (Selection < b.numberOfChoices);
while (Selection > b.numberOfChoices || Selection < 0) {
System.out.println("Error. Try again");
System.out.println("Your answer?: ");
Selection = in.nextInt();
}
}
}
和问题类：
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
public class Question {
int correctAnswer;
int numOfTries;
int numOfCorrectTries;
int numberOfChoices;
String Question;
String[] answerChoices;
public Question() {
}
public void getQuestion() {
System.out.println("Question: " + Question);
System.out.println("Answer: ");
for (int i = 0; i < numberOfChoices; i++) {
System.out.println(answerChoices[i]);
}
}
public double getPercentageRight() {
double percentageRight = (numOfCorrectTries / numOfTries) * 100;
percentageRight = Math.round(percentageRight * 100);
percentageRight = percentageRight / 100;
return percentageRight;
}
}
QUIZ.TXT：
How many licks does it take to get to the tootsie roll center of a
tootsie pop?
4
one
two
three
four
2
14
5
What is your name?
3
Arthur, King of the Britons
Sir Lancelot the Brave
Sir Robin the Not-Quite-So-Brave-As-Sir Lancelot
0
14
6
Who's on first?
5
What
Why
Because
Who
I don't know
3
14
7
Which of the following is a terror of the fire swamp?
4
Lightning sand
Flame spurt
R.O.U.S.
All of the above
3
14
4
Who is the all-time greatest pilot?
6
Manfred von Richthofen
Chuck Yeager
Hiraku Sulu
Luke Skywalker
Kara Thrace
Charles Lindbergh
4
14
9
答案 0 :(得分：1)
一些问题：
您的List<String> question = new ArrayList<String>();应该类似于List<Question> questionBank = new ArrayList<Question>();，因为将所有内容保存为字符串（而不是问题对象）会非常麻烦。在阅读代码时，名称questionBank也比question更具描述性。我还建议将questionBank作为类变量，以便在Quiz课程中轻松访问。
您永远不会将问题添加到您的ArrayList中，但我怀疑您已经知道这一点，并且在解决其他问题时它只是低优先级。
你的Question课程也有点不同寻常。构建它的更好方法可能是这样的：
public class Question {
private int correctAnswer;
private int numOfTries;
private int numOfCorrectTries;
private String question;
private String[] answerChoices;
public Question(String question, String[] answerChoices,
int correctAnswer, int numOfTries, int numOfCorrectTries) {
this.question = question;
this.answerChoices = answerChoices;
this.correctAnswer = correctAnswer;
this.numOfTries = numOfTries;
this.numOfCorrectTries = numOfCorrectTries;
}
public void getQuestion() {
System.out.println("Question: " + question);
System.out.println("Answer: ");
for (int i = 0; i < answerChoices.length; i++) {
System.out.println(answerChoices[i]);
}
}
public double getPercentageRight() {
double percentageRight = (numOfCorrectTries / numOfTries) * 100;
percentageRight = Math.round(percentageRight * 100);
percentageRight = percentageRight / 100;
return percentageRight;
}
}
我删除了numberOfChoices的变量，因为它与answerChoices.length相同。我还将您的Question重命名为question，因为Java中的变量通常遵循camelCase。我不确定其他方法是什么，或者它们应该如何显示输出，所以我主要是让它们独自存在。
对于读取文件，我认为你可以做一些与你所拥有的类似的东西，但是我会发布符合Question类的新构造函数的代码。
private void addQuestions() {
File quizText = new File("quiz.txt");
try {
Scanner fileIn = new Scanner(quizText);
while (fileIn.hasNextLine()) {
String question = fileIn.nextLine();
int numberOfAnswers = fileIn.nextInt();
fileIn.nextLine();
String[] answers = new String[numberOfAnswers];
for (int i = 0; i < numberOfAnswers; i++) {
answers[i] = fileIn.nextLine();
}
int correctAnswer = fileIn.nextInt();
int numOfTries = fileIn.nextInt();
int numOfCorrectTries = fileIn.nextInt();
fileIn.nextLine();
Question nextQuestion =
new Question(question, answers, correctAnswer, numOfTries, numOfCorrectTries);
questionBank.add(nextQuestion);
}
fileIn.close();
} catch (IOException e){
e.printStackTrace();
System.out.println("File Not Found.");
return;
}
}
我还将变量设为私有，但您可以为它们创建自定义getter，以防止它们从外部直接访问（和/或更改）。使用此代码，我能够创建一个包含所有五个问题的问题库，并显示正确的答案以及所有可能的选择，因此希望它指向正确的方向。
答案 1 :(得分：0)
我重新上课了。在我的例子中，您回答了上述所有问题。我将逐一解释它们。
public class Quiz {
List<Question> question = new ArrayList<Question>();
public void writeFile() {
Question qn = new Question();
try {
PrintWriter out = new PrintWriter("quiz.txt");
out.println(qn.Question);
out.println(qn.numberOfChoices);
qn.answerChoices = new String[qn.numberOfChoices];
for (int i = 0; i < qn.numberOfChoices; i++) {
out.println(qn.answerChoices[i]);
}
out.println(qn.correctAnswer);
out.println(qn.numOfTries);
out.println(qn.numOfCorrectTries);
out.close();
} catch (IOException f) {
System.out.println("Error.");
}
qn.getQuestion();
}
public void readFile() {
File file = new File("quiz.txt");
boolean exists = file.exists();
Quiz q = new Quiz();
Question a = new Question();
String[] answerChoices;
try {
if (exists == true) {
Scanner s = new Scanner(file);
String line = "";
while (s.hasNextLine()) {
line = s.nextLine();
if (line.startsWith("---")) {
a = new Question();
a.Question = line.substring(4);
} else if (line.startsWith("choices : ")) {
a.numberOfChoices = Integer.parseInt(line.substring(10).trim());
a.answerChoices = new String[a.numberOfChoices];
for (int i = 0; i < a.numberOfChoices; i++) {
a.answerChoices[i] = s.nextLine();
}
} else if (line.startsWith("correct answer : ")) {
a.correctAnswer = Integer.parseInt(line.substring(17).trim());
} else if (line.startsWith("No of Tries : ")) {
a.numOfTries = Integer.parseInt(line.substring(14).trim());
} else if (line.startsWith("No of correct Tries : ")) {
a.numOfCorrectTries = Integer.parseInt(line.substring(22).trim());
question.add(a);
}
}
} else {
q.writeFile();
}
} catch (IOException e) {
System.out.println("File not found.");
}
}
public static void main(String[] args) {
Quiz qz = new Quiz();
qz.readFile();
Question b = new Question();
int selection;
//real program starts here
System.out.println("Welcome to the Quiz Program! Good luck!");
System.out.println("****************************************");
b = qz.question.get(2); // you can implement how your questions are taken from list of questions
b.getQuestion();
Scanner in = new Scanner(System.in);
System.out.print("Your answer?: ");
selection = in.nextInt();
if (selection == b.correctAnswer) {
b.numOfCorrectTries++;
System.out.println("Correct answer");
} else {
System.out.println("Incorrect answer");
}
}
}
1）从文件加载测验问题并存储在arraylist中并访问它（需要帮助！）
而不是使用
List<String> question = new ArrayList<String>();
使用以下作为类变量。所以你可以在课堂的任何地方访问它们
List<Question> question = new ArrayList<Question>();
2）不接受正确答案 - 给我错误（逻辑错误）
逻辑在主块中得到纠正。
3）并非显示所有答案选项
重新读了readFile（）方法。但要想成功使用这个逻辑，你需要重新创建你的quiz.txt，如下所示。
--- How many licks does it take to get to the tootsie roll center of a tootsie pop?
choices : 4
one
two
three
four
correct answer : 2
No of Tries : 14
No of correct Tries : 5
--- What is your name?
choices : 3
Arthur, King of the Britons
Sir Lancelot the Brave
Sir Robin the Not-Quite-So-Brave-As-Sir Lancelot
correct answer : 0
No of Tries : 14
No of correct Tries : 6
--- Who's on first?
choices : 5
What
Why
Because
Who
I don't know
correct answer : 3
No of Tries : 14
No of correct Tries : 7
--- Which of the following is a terror of the fire swamp?
choices : 4
Lightning sand
Flame spurt
R.O.U.S.
All of the above
correct answer : 3
No of Tries : 14
No of correct Tries : 4
--- Who is the all-time greatest pilot?
choices : 6
Manfred von Richthofen
Chuck Yeager
Hiraku Sulu
Luke Skywalker
Kara Thrace
Charles Lindbergh
correct answer : 4
No of Tries : 14
No of correct Tries : 9
注意： 问题的选择基于
b = qz.question.get(2);
在main（）中。要根据随机选择的问题创建问题文件，您可以创建一个单独的方法并从该方法中提示问题。请进一步参考Math.random（）。
还可以为这种应用程序创建XML文件而不是txt。 Google for＆＃34; Java and XML＆＃34;
希望这有帮助。