Question

代码应输出Farenheit和Celsius的表格

public static void main(String[] args) {
    System.out.println("Fahrenheit\tCelsius");
    System.out.println("=======================");
     for(int temp = -45; temp <= 120; temp += 5) //for(int i = 0; i <= 100; i+= 10)
        {
            System.out.printf("%5d       |",          temp);
            double sum = (temp + (9.0/5.0)) * 32;   
            System.out.printf("%5d", (int)sum );
            System.out.printl

n();

Answer 1

你应该在一个包含while循环的地方完成这一切。

while循环伪代码是这样的：

string answer = "";
While (answer != quit)
{
answer = (ask question to user)
if (answer != quit)
   compute/display response
}

Answer 2

看起来你的大括号没有正确打开和关闭。此外，每次迭代都会重置userScore和totalScore。所以你没有得到合适的分数。把它移到循环外面。

import java.util.Scanner;

public class Multiplication {

    private static String question;
    private static Scanner input;
    private static Scanner scanner;
    private static int totalScore;
    private static int answer1;
    private static int userScore;

    public static void main(String[] args) {
        int number1;
        int number2;
        totalScore = 0;
        userScore = 0;
        input = new Scanner(System.in);
        do {
            number1 = (int)(Math.random() * 10);
            number2 = (int)(Math.random() * 10);    

            System.out.print("What is " + number1 + " * " + number2 + "? ");
            int answer = input.nextInt();
            while (number1 * number2 != answer) 
            {
                int answer1 = number1 * number2;
                System.out.println("Incorrect. The answer is " + answer1+".");
                System.out.print("Want more questions yes or no? ");
                scanner = new Scanner (System.in);
                question = scanner.next();
                totalScore++;
                break;
            } 

            if (number1 * number2 == answer)
            { 
                System.out.println("Correct. Nice work!");
                System.out.print("Want more questions yes or no? ");
                scanner = new Scanner (System.in);
                question = scanner.next(); 
                userScore++;
                totalScore++;
            }

        }while(question.equals("yes") || question.equals("y"));
        System.out.println("You have this many questions correct:" + userScore +" out of " + totalScore);
    }
}

更好的实施

这里的代码看起来更具可读性，并且删除了一些不必要的代码行。

import java.util.Scanner;

public class Multiplication {

    private static final Scanner scanner = new Scanner (System.in);
    private static int totalScore = 0;
    private static int userScore = 0;
    private static int number1;
    private static int number2;
    private static int answer;

    public static boolean continueExe(){
        String question;
        System.out.print("Want more questions yes or no? ");
        question = scanner.next();
        return (question.equals("yes") || question.equals("y"));        
    }

    public static void printOutput(){
        System.out.println("You have this many questions correct:" + userScore +" out of " + totalScore);
    }

    public static void askQuestion(){
        number1 = (int)(Math.random() * 10);
        number2 = (int)(Math.random() * 10);
        System.out.print("What is " + number1 + " * " + number2 + "? ");
    }

    public static void readAnswer(){
        answer = scanner.nextInt();
    }

    public static void isAnswerCorrect(){
        if (number1 * number2 != answer){
            System.out.println("Incorrect. The answer is " + number1 * number2 +".");
        }else{
            userScore++;
            System.out.println("Correct. Nice work!");
        }
        totalScore++;
    }

    public static void main(String[] args) {
        do{
            askQuestion();
            readAnswer();
            isAnswerCorrect();
        }while(continueExe());
        printOutput();
    }
}

Answer 3

错误是你打开'{'两次'if'statement -

if (question.equals("no")||question.equals("n")&& (number1 * number2 == answer)){ 
{

并忘了在最后一行关闭一个括号。

下面的代码解决了由括号引起的错误：

import java.util.Scanner;

public class Program3_3 {

private static String question;
private static Scanner input;
private static Scanner scanner;
private static int totalScore;
private static int answer1;
private static int userScore;

public static void main(String[] args) {
do {
    int number1 = (int)(Math.random() * 10);
    int number2 = (int)(Math.random() * 10);    
    totalScore = 0;
    userScore = 0;
    input = new Scanner(System.in);
    System.out.print("What is " + number1 + " * " + number2 + "? ");
    int answer = input.nextInt();
    while (number1 * number2 != answer) {
        int answer1 = number1 * number2;
        System.out.println("Incorrect. The answer is " + answer1+".");
        System.out.print("Want more questions yes or no? ");
        scanner = new Scanner (System.in);
        question = scanner.next(); 
        break;
     } 

    if (number1 * number2 == answer){ 
        System.out.println("Correct. Nice work!");
        System.out.print("Want more questions yes or no? ");
        scanner = new Scanner (System.in);
        question = scanner.next(); 
        }
    if (question.equals("no")||question.equals("n")&& (number1 * number2 == answer))
    {
        userScore++;
        totalScore++;
          System.out.println("You have this many questions correct:" + totalScore);
       }
} 
   while(question.equals("yes") || question.equals("y"));
    }
 }

提出乘法问题并用Java计算答案总数

3 个答案: