php定义一个矩形类rectangle,c#定义一个类圆Circle或者定义一个矩形类Rectangle,分别计算它们的周长和面积....

PHP定义一个矩形类Rectangle：

class Rectangle {
    private $length;
    private $width;
    
    public function __construct($length, $width) {
        $this->length = $length;
        $this->width = $width;
    }
    
    public function getArea() {
        return $this->length * $this->width;
    }
    
    public function getPerimeter() {
        return 2 * ($this->length + $this->width);
    }
}

C#定义一个类圆Circle：

class Circle {
    private double radius;
    
    public Circle(double radius) {
        this.radius = radius;
    }
    
    public double GetArea() {
        return Math.PI * radius * radius;
    }
    
    public double GetPerimeter() {
        return 2 * Math.PI * radius;
    }
}

C#定义一个矩形类Rectangle：

class Rectangle {
    private double length;
    private double width;
    
    public Rectangle(double length, double width) {
        this.length = length;
        this.width = width;
    }
    
    public double GetArea() {
        return length * width;
    }
    
    public double GetPerimeter() {
        return 2 * (length + width);
    }
}

以上是计算矩形和圆的面积和周长的示例代码。