將對象數組傳遞到 java 中的另一個 object 並打印出來 java

Question

我有一個 class 補充，我已經為它創建了一系列補充。 現在我想將這個 object 傳遞到另一個 class 雜志，其中一個雜志的實例有許多補充。 所以我希望能夠將這個補充對象數組傳遞給我的 Magazine 構造函數，並在 Magazine 中編寫一個方法，我可以使用它來顯示雜志名稱、成本以及它存儲的補充數組中的所有詳細信息。 我想我已經成功地將它作為參數傳遞了，但是我如何才能編寫一個能夠在其相關雜志旁邊顯示該數組的方法？

補充。java：

package javaapplication1;

import java.util.Arrays;

public class Supplement {
    private String supplementname;
    private int WeeklySupCost;
    private Supplement[] supplements;

    public void SetSupplementName(String supplementname){
        this.supplementname = supplementname;  
    };

    public void SetWeeklySupCost(int WeeklySupCost){
        this.WeeklySupCost = WeeklySupCost;
    };

    public String GetSupplementName(){
        return supplementname;
    };
    public int GetWeeklyCost(){
        return WeeklySupCost;
    };

    public Supplement(String supplementname, int WeeklySupCost){
        this.supplementname = supplementname;
        this.WeeklySupCost = WeeklySupCost;     
    };

    public void printSupplements(){
        System.out.println("Supplement: " + this.supplementname);
        System.out.println("Weekly Cost: " + this.WeeklySupCost); 
    }
}

雜志.java：

package javaapplication1;

public class Magazine {
    private String magazinename;
    private int WeeklyCost;
    private Magazine magazineobj;
    private Supplement[] supplements;

    public void SetMagazineName(String magazinename){
        this.magazinename = magazinename;    
    };

    public void SetWeeklyCost(int WeeklyCost){
        this.WeeklyCost = WeeklyCost;
    };

    public String GetMagazineName(){        
        return magazinename;
    };

    public int GetWeeklyCost(){        
        return WeeklyCost;
    };

    public Magazine(String magazinename, int WeeklyCost, Supplement[] supplements){
        this.magazinename = magazinename;
        this.WeeklyCost = WeeklyCost;
        this.supplements = supplements;
    };

    public Magazine(){};
    public void printMagazine(){
        System.out.println("Magazine Name: " + this.magazinename);
        System.out.println("Weekly Cost: " + this.WeeklyCost);
        System.out.println("Supplements: " + supplements[this.supplements]);    
    }
}

主程序：

package javaapplication1;

public class JavaApplication1 {
    public static void main(String[] args) {
        Supplement[] supplements = new Supplement[4];

        supplements[0] = new Supplement("Sports Illustrated Special", 4);
        supplements[1] = new Supplement("Health and Nutrition", 2);
        supplements[2] = new Supplement("Lifestyled", 5);
        supplements[3] = new Supplement("Gamer's Update", 3);

        Magazine magazineobj = new Magazine("The Wheels Special", 35, supplements);
        for(int i = 0; i < 4; i++){
            magazineobj.printMagazine();
            supplements[i].printSupplements();   
        }
        //System.out.println(magazineobj);
    }
}

Answer 1

而是使用printMethod()使用 Object class 的toString()方法並在 class 中覆蓋。

public class Magazine {

    @Override
    public String toString() {
        String str = "Magazine Name: " + magazinename + "\nWeekly Cost: " + WeeklyCost + "\nSupplements: ";
        for (Supplement supplement : supplements) {
            str += supplement;
        }
        return str;
    }

//    public void printMagazine(){
//        System.out.println("Magazine Name: " + this.magazinename);
//        System.out.println("Weekly Cost: " + this.WeeklyCost);
//        System.out.println("Supplements: " + supplements[this.supplements]);    
//    }

}

class Supplement {

    @Override
    public String toString() {
        return "Supplement: " + supplementname + "\nWeekly Cost: " + WeeklySupCost;
    };

//    public void printSupplements(){
//        System.out.println("Supplement: " + this.supplementname);
//        System.out.println("Weekly Cost: " + this.WeeklySupCost); 
//    }
}

// In Main
//for(int i = 0; i < 4; i++){
//    magazineobj.printMagazine();
//    supplements[i].printSupplements();   
//}
System.out.println(magazineobj);

Answer 2

要打印數組的元素，可以使用Arrays.toString(arr) 。 請找到以下代碼並檢查它是否滿足您的要求。

補充。java

    import java.util.Arrays;
    public class Supplement {
    private String supplementname;
    private int WeeklySupCost;
    private Supplement[] supplements;

    public void SetSupplementName(String supplementname) {
        this.supplementname = supplementname;
    }

    public void SetWeeklySupCost(int WeeklySupCost) {
        this.WeeklySupCost = WeeklySupCost;
    }

    public String GetSupplementName() {
        return supplementname;
    }

    public int GetWeeklyCost() {
        return WeeklySupCost;
    }

    public Supplement(String supplementname, int WeeklySupCost) {
        this.supplementname = supplementname;
        this.WeeklySupCost = WeeklySupCost;
    }

    public void printSupplements() {
        System.out.println("Supplement: " + this.supplementname);
        System.out.println("Weekly Cost: " + this.WeeklySupCost);
        System.out.println("supplements: " + Arrays.toString(this.supplements));
    }
    @Override
    public String toString() {
        return "Supplement{" +
            "supplementname='" + supplementname + '\'' +
            ", WeeklySupCost=" + WeeklySupCost +
            ", supplements=" + Arrays.toString(supplements) +
            '}';
    }
}

雜志.java ：

import java.util.Arrays;
public class Magazine {
    private String magazinename;
    private int WeeklyCost;
    private Magazine magazineobj;
    private Supplement[] supplements;

    public void SetMagazineName(String magazinename) {
        this.magazinename = magazinename;
    }

    public void SetWeeklyCost(int WeeklyCost) {
        this.WeeklyCost = WeeklyCost;
    }

    public String GetMagazineName() {
        return magazinename;
    }

    public int GetWeeklyCost() {
        return WeeklyCost;
    }

    public Magazine(String magazinename, int WeeklyCost, Supplement[] supplements) {
        this.magazinename = magazinename;
        this.WeeklyCost = WeeklyCost;
        this.supplements = supplements;
    }

    public Magazine() {
    }

    public void printMagazine() {
        System.out.println("Magazine Name: " + this.magazinename);
        System.out.println("Weekly Cost: " + this.WeeklyCost);
        System.out.println("Supplements: " + Arrays.toString(this.supplements));
    }

}

Main.java :

public class Main {
    public static void main(String[] args) {
        Supplement[] supplements = new Supplement[4];
        supplements[0] = new Supplement("Sports Illustrated Special", 4);
        supplements[1] = new Supplement("Health and Nutrition", 2);
        supplements[2] = new Supplement("Lifestyled", 5);
        supplements[3] = new Supplement("Gamer's Update", 3);

        Magazine magazineobj = new Magazine("The Wheels Special", 35, supplements);
        for (int i = 0; i < 4; i++) {
            magazineobj.printMagazine();
            supplements[i].toString();
        }
    }
}

您還可以使用toString()方法打印上述對象的值。

Answer 3

使用ArrayList是不是簡單多了？ 往下看：

Supplement class：

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Supplement {
    private String supplementname;
    private int WeeklySupCost;
    public Supplement(String supplementname, int weeklySupCost) {
        this.supplementname = supplementname;
        WeeklySupCost = weeklySupCost;
    }
    public String getSupplementname() {
        return supplementname;
    }
    public void setSupplementname(String supplementname) {
        this.supplementname = supplementname;
    }
    public int getWeeklySupCost() {
        return WeeklySupCost;
    }
    public void setWeeklySupCost(int weeklySupCost) {
        WeeklySupCost = weeklySupCost;
    }
    @Override
    public String toString() {
        return "Supplement [supplementname=" + supplementname + ", WeeklySupCost=" + WeeklySupCost + "]";
    }


}

Magazine class：

public class Magazine {
    private String magazinename;
    private int WeeklyCost;
    private List<Supplement> list;
    public Magazine(String magazinename, int weeklyCost, List<Supplement> list) {
        this.magazinename = magazinename;
        WeeklyCost = weeklyCost;
        this.list = list;
    }
    public String getMagazinename() {
        return magazinename;
    }
    public void setMagazinename(String magazinename) {
        this.magazinename = magazinename;
    }
    public int getWeeklyCost() {
        return WeeklyCost;
    }
    public void setWeeklyCost(int weeklyCost) {
        WeeklyCost = weeklyCost;
    }
    public List<Supplement> getList() {
        return list;
    }
    public void setList(List<Supplement> list) {
        this.list = list;
    }
    @Override
    public String toString() {
        return "Magazine [magazinename=" + magazinename + ", WeeklyCost=" + WeeklyCost + ", list=" + list + "]";
    }



}

JavaApplication1 class：

import java.util.ArrayList;
import java.util.List;

public class JavaApplication1 {
    public static void main(String[] args) {
        List<Supplement> supplements = new ArrayList<Supplement>();

        supplements.add(new Supplement("Sports Illustrated Special", 4));
        supplements.add(new Supplement("Health and Nutrition", 2));
        supplements.add(new Supplement("Lifestyled", 5));
        supplements.add(new Supplement("Gamer's Update", 3));

        Magazine magazineobj = new Magazine("The Wheels Special", 35, supplements);

        System.out.println(magazineobj);

        //System.out.println(magazineobj);
    }
}

output 是：

Magazine [magazinename=The Wheels Special, WeeklyCost=35, list=[Supplement [supplementname=Sports Illustrated Special, WeeklySupCost=4], Supplement [supplementname=Health and Nutrition, WeeklySupCost=2], Supplement [supplementname=Lifestyled, WeeklySupCost=5], Supplement [supplementname=Gamer's Update, WeeklySupCost=3]]]

您可以更改toString()方法以顯示您希望的內容，並且可以大大減少代碼。