來自主 class 的輸入無法在另一個 class 中訪問，只會顯示初始化值

Question

我需要訪問主要 class 的輸入，並將它們應用到部門 class，但是，它不允許我。 另外，我不允許使用參數。 我需要遵循這個 UML 圖。 請指導我如何解決這個問題。 我們的主題是關於 inheritance、static 變量和方法、方法覆蓋和 super 關鍵字。

public class Department {
    private int groupScore;
    private double groupAverage;
    private static int overallScore;
    private static double overallAverage;
    
    public Department(){
        int a = 0; 
        int b = 0; 
        int c = 0; 
        int d = 0; 
        int e = 0;
        
        int gscore = groupScore;
        gscore = a + b + c + d + e;
        
        int oascore = overallScore;
        oascore = overallScore + groupScore;
        
        overallAverage = overallAverage/10.0;
        
        groupAverage = groupScore/5.0;
    }
    public double getGroupAverage() {
        return groupAverage;
    }
    public static void displayAverage() {
        double oave = overallAverage;
        System.out.println("Overall Average: " + oave);
    }
}

import java.util.Scanner;
public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Department objdept = new Department();
        
        System.out.println("Enter 5 rates for Department A (1-5)");
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        int d = sc.nextInt();
        int e = sc.nextInt();
        System.out.println("Department 1 group average: " + objdept.getGroupAverage());
        objdept.getGroupAverage();
        objdept.displayAverage();
        System.out.println();
        System.out.println("Enter 5 rates for Department B (1-5)");
        int f = sc.nextInt();
        int g = sc.nextInt();
        int h = sc.nextInt();
        int i = sc.nextInt();
        int j = sc.nextInt();
        objdept.getGroupAverage();
        System.out.println("Department 2 group average: "+ objdept.getGroupAverage());
        System.out.println();
        Department.displayAverage();
    }
}

Answer 1

如果您不允許在基於圖表的構造函數中使用 arguments。 您可以將掃描器代碼添加到 Department 構造函數中。 然后主要創建兩個不同的部門對象。

public Department(){
    Scanner sc = new Scanner(System.in);
    int a = sc.nextInt();
    int b = sc.nextInt();
    // c,d,e etc...
    groupScore = a + b + c + d + e;
    groupAverage = groupScore / 5.0;

    overallScore = overallScore + groupScore;

    if (overallAverage == 0.0) {
        overallAverage = groupAverage;
    } else {
        overallAverage = (groupAverage + overallAverage) / 2.0;
    }
}

public class Main {
    public static void main(String[] args) {
        System.out.println("Enter 5 rates for Department 1 (1-5)");
        Department department1 = new Department();
        System.out.println("Department 1 group average: " + department1.getGroupAverage());
        Department.displayAverage();
        System.out.println();

        System.out.println("Enter 5 rates for Department 2 (1-5)");
        Department department2 = new Department();
        System.out.println("Department 2 group average: " + department2.getGroupAverage());
        Department.displayAverage();
    }
}

如果允許 arguments ，則需要在創建 object 時將變量傳遞到 Department 構造函數中。首先創建一個構造函數，它接受 5 個 integer 值

public Department(int a, int b, int c, int d, int e){
    groupScore = a + b + c + d + e;
    groupAverage = (a + b + c + d + e) / 5;
}

其次將值傳遞給 main 方法中的構造函數。 像這樣

int a = sc.nextInt();
int b = sc.nextInt();
int c = sc.nextInt();
int d = sc.nextInt();
int e = sc.nextInt();
Department objdept = new Department(a,b,c,d,e);