java - 用户输入的总分、平均分、最低分和最高分(条件控制结构)

Question

我有以下家庭作业。我们的老师教得不好，所以我需要额外的帮助。

编写一个 Java 程序，输入一名学生在 5 个测验中的 5 个分数。输出五个分数的总和和平均值。确定并显示最高和最低分数。

这就是我现在陷入困境的原因。上次我只显示了 Q3，它只显示平均分和最低分，没有最高分。请帮助我完成这项工作!

import java.util.Scanner;
import java.io.*;

class Quizzes
{

    public static void main(String[] args) {
    int Q1, Q2, Q3, Q4, Q5;
    double average;

    Scanner keyboard = new Scanner(System.in);
    System.out.print("Enter Quizzes: ");
    Q1 = keyboard.nextInt();
    Q2 = keyboard.nextInt();
    Q3 = keyboard.nextInt();
    Q4 = keyboard.nextInt();
    Q5 = keyboard.nextInt();

    average = (Q1 + Q2 + Q3 + Q4 + Q5) / 5;
    System.out.println("Average Score is: " + average);

    if (Q1 < Q2 && Q1 < Q3) {
        System.out.println("The lowest score is: " + Q1);
    } else if (Q2 < Q1 && Q2 < Q3) {
        System.out.println("The lowest score is: " + Q2);
    } else if (Q3 < Q1 && Q2 < Q3) {
        System.out.println("The lowest score is: " + Q3);
    } else if (Q1 > Q2 && Q1 > Q3) {
        System.out.println("The highest score is: " + Q1);
    } else if (Q2 > Q1 && Q2 > Q3) {
        System.out.println("The highest score is: " + Q2);        
    } else if (Q3 > Q3 && Q1 > Q2) {
        System.out.println("The highest score is: " + Q3);
    } else {
        System.out.println("The lowest score is: " + Q3);
    }

  }
}

Answer 1

在您当前的解决方案中，您有几个基本问​​题，例如 else if (Q3 > Q3)。

您也不检查是否相等，即 if (Q2 >= Q3)。

您当前技术的主要问题是您有大量 if/else 语句，更好的解决方案是使用如下所示的数组:

public class Quizzes {

    public static void main(String[] args) {

        double Q1, Q2, Q3, Q4, Q5;
        double average = 0;
        double max = 0;
        double count = 0;
        double[] userInput = new double[5];

        Scanner keyboard = new Scanner(System.in);
        System.out.print("Enter Quizzes: ");
        System.out.println("");
        Q1 = keyboard.nextInt();
        userInput[0] = Q1;
        Q2 = keyboard.nextInt();
        userInput[1] = Q2;
        Q3 = keyboard.nextInt();
        userInput[2] = Q3;
        Q4 = keyboard.nextInt();
        userInput[3] = Q4;
        Q5 = keyboard.nextInt();
        userInput[4] = Q5;
        keyboard.close();

        for (int i = 0; i < userInput.length; i++) {
            count = count + userInput[i];
            average = count / 5;
        }
        System.out.println("Average Score is: " + average);
        Arrays.sort(userInput);
        System.out.println("The lowest score is: " + userInput[0]);
        max = userInput[userInput.length - 1];
        System.out.println("The highest score is: " + max);
    }

}

编辑:

既然您已经通知我们您不能使用数组，那么下面的代码将完成这项工作，而无需过多修改您的原始方法:

public class Quizzes {

    public static void main(String[] args) {

        double Q1, Q2, Q3, Q4, Q5;
        double average = 0;
        double lowest = 0;

        Scanner keyboard = new Scanner(System.in);
        System.out.print("Enter Quizzes: ");
        System.out.println("");
        Q1 = keyboard.nextDouble();
        Q2 = keyboard.nextDouble();
        Q3 = keyboard.nextDouble();
        Q4 = keyboard.nextDouble();
        Q5 = keyboard.nextDouble();
        keyboard.close();

        average = (Q1 + Q2 + Q3 + Q4 + Q5) / 5;
        System.out.println("Average Score is: " + average);

        if (Q1 <= Q2 && Q1 <= Q3 && Q1 <= Q4 && Q1 <= Q5) {
            lowest = Q1;
        } else if (Q2 <= Q1 && Q2 <= Q3 && Q2 <= Q4 && Q2 <= Q5) {
            lowest = Q2;
        } else if (Q3 <= Q1 && Q3 <= Q2 && Q3 <= Q4 && Q3 <= Q5) {
            lowest = Q3;
        } else if (Q4 <= Q1 && Q4 <= Q2 && Q4 <= Q3 && Q4 <= Q5) {
            lowest = Q4;
        } else if (Q5 <= Q1 && Q5 <= Q2 && Q5 <= Q3 && Q5 <= Q4) {
            lowest = Q5;
        }

        System.out.println("The lowest score is: " + lowest);
        // THEN DO SIMILAR TO GET HIGHEST SCORE
    }
}