c# 设计一个类shape(抽象的),设计其两个子类,circle(圆形)类和square...

以贴的代码来看存在以下问题：1.main函数后面直接带分号，导致主函数只有声明，没有实现。2.pi可以定义一个全局的宏，不需要重复定义。3.输出的面积shape1,shape2在语句块中并没有定义，建议直接使用类的求面积方法。4.正方形的面积难道不是一条边的平方？以上几点问题希望能给你有所帮助。

delete arr;arr 是数组，释放内存的语法是：delete[] arr;

square(float len):rectangle(len,len){};~square(){};float area(float len){ return len * len;};};float total(shape*s[],int n){ float sum=0.0;for(int i=0;i<n;i++)sum+=s[i]->area();return sum;} int main(){ shape* s[2];s[0]=new circle(1);cout<area()...

Circle(double r):radius(r){} double ShowArea(){return PI*radius*radius;} };class Rectangle:public Shape { private:double length;double width;public:Rectangle(double l, double w):length(l), width(w){} double ShowArea(){return length*width;} };class Square:public Shape { pri...

// 接口类public interface Shpe{ public double area(double num );}//实现类-正方形 public class Square implements Shpe{ @Override public double area( double num ){ return num * num; }}//实现类-圆 public class Circle implements Shpe{ @Override public double ...

private class Square : Shape { public double Side { get; set; } public override void ShowArea(){ Console.WriteLine(Math.Pow(this.Side, 2D));} } private class Circle : Shape { public double Radium { get; set; } public override void ShowArea(){ Console.WriteLine(3.14 * ...

(2);\x0d\x0aRectangle rect(3,4);\x0d\x0aSquare square(5);\x0d\x0a\x0d\x0aShape * arr[3] = {&circle, &rect, &square};\x0d\x0a\x0d\x0afor(int i=0; i<3; i++)\x0d\x0a{\x0d\x0acout << arr[i]->ShowArea() << endl;\x0d\x0a}\x0...

从无到有，只需一行代码：Shape circle = ShapeFactory.createShape(Shape.Type.Circle);2. 工厂方法模式：扩展与选择的智慧与简单工厂类似，但这次，我们引入了接口或抽象类，让决定创建哪个子类的对象权衡交给更高层次的设计。这种灵活性使得代码更加可扩展和易于维护。设计更进一步，接口与选择：Shape ...

method stubSystem.out.println(Math.PI * r * r);}}public class DroolsTest {public static final void main(String[] args) { Shape rect = new Rectangle(4,5); Shape square = new Square(5); Shape circle = new Circle(5); rect.showArea(); square....

//圆形 class Roundness: public Shape{ public:Roundness(float r):radius(r){} virtual float CalCircumference(){ return 2 * PI * radius;} virtual float CalArea(){ return PI * radius * radius;} private:float radius;};//正方形 class Square: public Shape{ public:Square(float w)...