java - 是否可以将 int 转换为自定义类类型(在 java 中)？如果是那么怎么办？

Question

我是 java 初学者，试图创建一个抽象类 Shape 的抽象方法 abstract int area()，Shape 类扩展到其他三个类和这些类的覆盖区域方法正在计算面积并返回 int 值，我想存储在 Shape 类数组中。

import java.util.Scanner;
abstract class Shape{
abstract int area();
}

class Ractangle extends Shape {
    private int length,width;
    public Rectangle(){
        System.out.println("Enter length rectangle ");
        this.length = Test.scan.nextInt();
        System.out.println("Enter width rectangle ");
        this.width = Test.scan.nextInt();
    }
    public int area(){
    return length*width;
    }
}

class Square extends Shape{
    private int side;
    public Square(){
        System.out.println("Enter side square ");
        this.side = Test.scan.nextInt();
    }
    public int area(){
        return side*side;
    }
}
class Parlellogram extends Shape{
    private int base,height;
    public Parallelogram(){
        System.out.println("Enter base parallelogram");
        this.base = Test.scan.nextInt();
        System.out.println("Enter height parallelogram ");
        this.height = Test.scan.nextInt();
    }
    public int area(){
        return base*height;
    }
}
class Test{
    public static Scanner scan;
    public static void main(String[] args){
        scan = new Scanner(System.in);
        Rectangle rect = new Rectangle();
        Square sq = new Square();
        Parallelogram prlg = new Parallelogram();

        Shape[] shapeArray = {rect.area(), sq.area(), prlg.area()}; //error here

        //shapeArray[0] = rect.area();
        //shapeArray[1] = sq.area();
        //shapeArray[2] = prlg.area();
    }
}

错误:类型不兼容:无法将 int 转换为 Shape

Answer 1

也许是想写这个？

int[] shapeArray = {ract.area(), sq.area(), prlg.area()};

还是 tihs？

Shape[] shapeArray = {ract, sq, prlg};

如果您计算一个形状的面积，您将不再有一个 Shape，而是一个 int。