Java 矩形类：计算周长和面积

下面是Java语言的代码实现：

public class Rectangle {
    private double width;
    private double height;
    
    public Rectangle(double width, double height) {
        this.width = width;
        this.height = height;
    }
    
    public double getPerimeter() {
        return 2 * (width + height);
    }
    
    public double getArea() {
        return width * height;
    }
    
    public static void main(String[] args) {
        Rectangle rectangle = new Rectangle(5, 3);
        double perimeter = rectangle.getPerimeter();
        double area = rectangle.getArea();
        System.out.println('矩形的周长为：' + perimeter);
        System.out.println('矩形的面积为：' + area);
    }
}

运行结果：

矩形的周长为：16.0
矩形的面积为：15.0