第三题创建test，输入正整数n

package shiyan6.test;

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

public class Test1 {
    private double width;//宽度
    private double height;//高度

    public double getWidth() {
        return width;
    }

    public void setWidth(double width) {
        this.width = width;
    }

    public double getHeight() {
        return height;
    }

    public void setHeight(double height) {
        this.height = height;
    }

    //求面积
    public double getArea() {
        return this.width * this.height;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("***********程序输入*************");
        System.out.print("请输入需要创建的矩形数量：");
        int n = scanner.nextInt();
        Test1 test1;
        List<Test1> list = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            test1 = new Test1();
            System.out.print("请输入第" + (i + 1) + "个矩形的宽：");
            test1.setWidth(scanner.nextDouble());
            System.out.print("请输入第" + (i + 1) + "个矩形的高：");
            test1.setHeight(scanner.nextDouble());
            list.add(test1);
        }
        System.out.println("***********程序输出*************");
        System.out.println("一共创建" + list.size() + "个矩形！");
        for (int i = 0; i < n; i++) {
            test1 = list.get(i);
            System.out.println("矩形" + (i + 1) + " 矩形的宽：" + test1.getWidth() + " 高：" + test1.getHeight() + " 面积：" + test1.getArea());
        }
        System.out.println("***********程序结束*************");
    }
}

package shiyan6.test;

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

public class Test1 {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        System.out.print("请输入需要创建矩形的数量:");
        int snum = sc.nextInt();
        List<Rectangle> rtList = new ArrayList<Rectangle>();
        for (int i = 1;i<=snum;i++){
            Rectangle rt = new Rectangle();
            System.out.print("请输入第"+i+"个矩形的宽：");
            double width = sc.nextDouble();
            rt.setWidth(width);
            System.out.print("请输入第"+i+"个矩形的高：");
            double height = sc.nextDouble();
            rt.setHeight(height);
            rt.setArea(width*height);
            rtList.add(rt);
        }
        int t =0;
        System.out.println("一共创建了"+snum+"个矩形");
        for (Rectangle rt: rtList
             ) {
            t++;
            System.out.println("矩形"+t+"的宽："+rt.getWidth()+"高："+rt.getHeight()+"面积："+rt.getArea());
        }
    }

}
class Rectangle{
    private double width;

    private double height;

    private double area;

    public double getWidth() {
        return width;
    }

    public void setWidth(double width) {
        this.width = width;
    }

    public double getHeight() {
        return height;
    }

    public void setHeight(double height) {
        this.height = height;
    }

    public double getArea() {
        return area;
    }

    public void setArea(double area) {
        this.area = area;
    }
}