计算数组

Question

我正在开发一个Java项目，该项目请求用户输入信息，如名称，ID，数组中的得分。我需要帮助计算用户输入的平均成绩以及如何找出得分最高的人。这是我的代码：

package finalproject;

import java.util.Scanner;

public class FinalProject {

    /**
     * @param args
     *            the command line arguments
     */

    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);
        Cis84[] student = new Cis84[50];

        int option;

        for (int c = 0; c < 50; c++)
            student[c] = new Cis84();

        do {
            System.out.print("");
            System.out.println("1) Add Information");
            System.out.println("2) Show report");
            System.out.println("3) Exit");
            System.out.print("\nEnter option: ");

            option = input.nextInt();

            switch (option) {
            case 1:
                String n;

                double g;
                int index,
                i;

                System.out.println("Which position of the student?");
                index = input.nextInt();

                System.out.println("What is the student's name:");
                n = input.nextLine();
                n = input.nextLine();

                System.out.println("What is student's Id");
                i = input.nextInt();

                System.out.println("What is student's score");
                g = input.nextDouble();

                student[index].setName(n);
                student[index].setGrade(g);
                student[index].setId(i);
                break;

            case 2:
                for (int c = 0; c < 50; c++)
                    System.out.println(student[c]);
                break;
            case 3:
                System.out.println("You are done");
                break;
            default:
                System.out.println("Try again");
                break;
            }

        } while (option != 3);

    }
}

和班级

package finalproject;

public class Cis84 {
    private String name;
    private int id;
    private double grade;

    public Cis84() {
        name = "not input yet";
        id = 00000;
        grade = 0.0;
    }

    public Cis84(String n, int i, double g) {
        name = n;
        id = i;
        grade = g;
    }

    public void setName(String n) {
        name = n;
    }

    public void setId(int i) {
        id = i;
    }

    public void setGrade(double g) {
        grade = g;
    }

    public String getName() {
        return name;
    }

    public int getId() {
        return id;
    }

    public double getGrade() {
        return grade;
    }

    public String toString() {
        return String.format("%s\n%d\n%.2f\n", name, id, grade);
    }
}

Answer 1

很明显，这是为了完成家庭作业，我觉得给你一个直接的答案感觉不舒服。但是，您要做的是在显示平均值时，遍历整个students数组并总结得分，然后除以数组的大小，可能使用for循环。您可以通过在调用switch-case的选项1时随时增加计数器来跟踪数组的大小。

要找到最高分，您应该能够使用上面提到的平均值计算循环，并检查等级与上一个最高等级。记录最高等级的索引并将其打印出来。

有一些伪代码！

for(size of array which isn't NULL){
    add indexed grade to sum;
    check to see if this index has the highest grade;
}

display (sum/size); //the average
display highest grade;

Answer 2

计算平均值将类似于下面的代码。请记住，平均值是所有值之和除以值总数

 double sum = 0, divisor = 0;
    for (int k = 0; k < student.length; k++){
         sum += student[k].getGrade();//add up all the grades
         divisor = k;//get the number of total items
        }
    return sum/divisor; //divide

Answer 3

private static double calculateAverage(Cis84[] students) {

    double sum = 0;

    for (Cis84 student : students) {
        sum += student.getGrade();
    }

    return sum / students.length;
}

private static double calculateHighestScore(Cis84[] students) {

    double highestScore = 0;

    for (Cis84 student : students) {
        if (student.getGrade() > highestScore) {
            highestScore = student.getGrade();
        }
    }

    return highestScore;
}

然后，显示信息：

    case 2:
        System.out.println("Average:");
        System.out.println(calculateAverage(student));
        System.out.println("Highest score:");
        System.out.println(calculateHighestScore(student));