JAVA定义一个 Retangle类，有长、宽等属性，定义构造方法用来初始化类的这些属性，定义方法输出Retangle的长宽和面积。编写应用程序使用Retangle。 【输入形式】 Please input length: Please input width: 【输出形式】 The lengh is: The width is: The area is: 【输入样例】 4.0 3.0 【输出样例】 The lengh is:4.0 The width is:3.0 The area is:12.0

以下是JAVA代码实现：

import java.util.Scanner;

public class Retangle {
    private double length;
    private double width;
    
    public Retangle(double length, double width) {
        this.length = length;
        this.width = width;
    }
    
    public void print() {
        System.out.println("The lengh is:" + length);
        System.out.println("The width is:" + width);
        System.out.println("The area is:" + length * width);
    }
    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("Please input length:");
        double length = sc.nextDouble();
        System.out.println("Please input width:");
        double width = sc.nextDouble();
        Retangle r = new Retangle(length, width);
        r.print();
    }
}

运行结果：

Please input length:
4.0
Please input width:
3.0
The lengh is:4.0
The width is:3.0
The area is:12.0