如何在我的循环中找到所有测试分数的最高、最低和平均值？

Posted 2023-03-17

【中文标题】如何在我的循环中找到所有测试分数的最高、最低和平均值？

【英文标题】：How can I find the highest, lowest, and average value of all test scores within my loop?

【发布时间】：2018-08-01 09:12:57

【问题描述】：

下午好，或者当您阅读本文时。我试图弄清楚如何找到用户输入的最低、最高和平均测试分数。 我有一个循环来跟踪标记值，在我的例子中是 999。所以当用户输入 999 时，它会退出循环。我还通过检查用户是否输入超过 100 或低于 0 作为输入来进行某种程度的数据验证。但是，我的问题是，如何实现一种方法来获取此代码以找到我的用户输入所需的值。我的代码如下：

import java.util.Scanner;
public class TestScoreStatistics 


    public static void main(String[] args) 
    
        Scanner scn = new Scanner(System.in);
        int testScore;
        double totalScore = 0;
        final int QUIT = 999;
        final String PROMPT = "Enter a test score >>> ";
        int lowScore;
        int highScore;
        String scoreString = "";
        int counter = 0;

        System.out.print(PROMPT);
        testScore = scn.nextInt();

        while (testScore != QUIT)
        

            if (testScore < 0 || testScore > 100 )
            
                System.out.println("Incorect input field");

            
            else
            
                scoreString += testScore + " ";
                counter++;
            

            System.out.print(PROMPT);
            testScore = scn.nextInt();



        
        System.out.println(scoreString);
        System.out.println(counter + " valid test score(s)");

    

【问题讨论】：

你可以使用 java-8 的一些特性吗？

试试看ArrayList

如果是这样，那么您可以将分数存储到 List 实现中，然后您可以执行 IntSummaryStatistics summaryStatistics = myList.stream() .collect(Collectors.summarizingInt(Integer::intValue)); 然后使用 int max = summaryStatistics.getMax(); int min = summaryStatistics.getMin(); double average = summaryStatistics.getAverage(); 收集结果

【参考方案1】：

在保持您的代码几乎相同的同时，您可以这样做：

import java.util.Scanner;
public class TestScoreStatistics 


    public static void main(String[] args) 
    
        Scanner scn = new Scanner(System.in);
        int testScore;
        double totalScore = 0;
        final int QUIT = 999;
        final String PROMPT = "Enter a test score >>> ";
        int lowScore = 100; //setting the low score to the highest score possible
        int highScore = 0; //setting the high score to the lowest score possible
        String scoreString = "";
        int counter = 0;

        System.out.print(PROMPT);
        testScore = scn.nextInt();

        while (testScore != QUIT)
        

            if (testScore < 0 || testScore > 100 )
            
                System.out.println("Incorect input field");

            
            else
            
                scoreString += testScore + " ";
                counter++;
                //getting the new lowest score if the testScore is lower than lowScore
                if(testScore < lowScore)
                    lowScore = testScore;
                
                //getting the new highest score if the testScore is higher than highScore
                if(testScore > highScore)
                    highScore = testScore;
                
                totalScore += testScore; //adding up all the scores
            

            System.out.print(PROMPT);
            testScore = scn.nextInt();
         
        double averageScore = totalScore / counter; //getting the average
     

这将检查testScore 是高于还是低于最高和最低分数。该程序还将所有分数相加，然后除以计数器（即有多少次测试）得到平均值。

【讨论】：

这是一个非常优雅而简单的解决方案。

谢谢，只是尽量保持它接近您的代码。

【参考方案2】：

这就是我会这样做的方式。

// defines your prompt
private static String PROMPT = "Please enter the next number> ";

// validation in a separate method
private static int asInteger(String s)

    try
        return Integer.parseInt(s);
    catch(Exception ex)return -1;


// main method
public static void main(String[] args)


    Scanner scn = new Scanner(System.in);
    System.out.print(PROMPT);
    String line = scn.nextLine();

    int N = 0;
    double max = 0;
    double min = Integer.MAX_VALUE;
    double avg = 0;
    while (line.length() == 0 || asInteger(line) != -1)
    
        int i = asInteger(line);
        max = java.lang.Math.max(max, i);
        min = java.lang.Math.min(min, i);
        avg += i;
        N++;

        // new prompt
        System.out.print(PROMPT);
        line = scn.nextLine();
    
    System.out.println("max : " + max);
    System.out.println("min : " + min);
    System.out.println("avg : " + avg/N);

验证方法将（在其当前实现中）允许输入任何整数。一旦输入任何无法转换为数字的内容，它将返回 -1，这会触发主循环的中断。

主循环只是跟踪当前的运行总数（以计算平均值），以及到目前为止看到的最大值和最小值。

一旦退出循环，这些值就会简单地打印到System.out。

【参考方案3】：

只需对您的代码进行最少的更改：

public class Answer 

    public static void main(String[] args) 

        Scanner scn = new Scanner(System.in);
        int testScore;
        final int QUIT = 999;
        final String PROMPT = "Enter a test score >>> ";
        int maxScore = Integer.MIN_VALUE;
        int minScore = Integer.MAX_VALUE;
        double totalScore = 0;
        double avgScore = 0.0;
        int counter = 0;

        System.out.print(PROMPT);
        testScore = scn.nextInt();

        while (testScore != QUIT) 

            if (testScore < 0 || testScore > 100) 
                System.out.println("Incorect input field");

             else 
                counter++;
                System.out.println("The number of scores you entered is " + counter);
                //test for minimum
                if(testScore < minScore) minScore = testScore;
                System.out.println("Current minimum score = " + minScore);
                //test for maximum
                if(testScore > maxScore) maxScore = testScore;
                System.out.println("Current maximum score = " + maxScore);
                //calculate average
                totalScore += testScore;
                avgScore = totalScore / counter;
                System.out.println("Current average score = " + avgScore);
            

            System.out.print(PROMPT);
            testScore = scn.nextInt();