#include "stdafx.h"
#include <iostream>
#include <windows.h>
using namespace std;
class Shape
{
public:
    Shape(){};
    ~Shape(){};
    virtual float GetArea()
    {
        return -1;
    }
};
class Circle:public Shape
{
    Circle(float radius):isRadius(radius){};
    ~Circle(){};
    virtual float GetArea()
    {
        return (3.14*isRadius*isRadius);
    }
private:
    float isRadius;
};
class Rectangle1:public Shape
{
    Rectangle1(float len,float idth):islenght(len),iswidth(idth){};
    ~Rectangle1(){};
    virtual float GetArea()
    {
        return islenght*iswidth;
    }
    float getlenght()
    {
        return islenght;
    }
    float getwidth()
    {
        return iswidth;
    }
private:
    float islenght;
    float iswidth;
};
class Square:public Rectangle1
{
public:
    Square(float len){};
    ~Square(){}
};
Square::Square(float len):Rectangle1(len,len)
{

}

int _tmain(int argc, _TCHAR* argv[])
{
    Shape *sp;
    sp=new Circle(5);
    printf("圆的面积为%f\n",sp->GetArea());
    delete sp;
    sp=new Rectangle1(4,6);
    printf("矩形的面积为:%f\n",sp->GetArea());
    delete sp;
    sp=new Shape(5);
    printf("正方形的面积是:%f\n",sp->GetArea());
    delete sp;
    system("pause");
    return 0;
}
运行之后错误一大堆。请各位帮忙看一下。都是些最简单最基础的，应该很容易看得出来。错误提示就没有贴出来了。希望各位看了之后指出错在哪里 ，谢谢。

这些错误LZ应该去看书。。根据错误提示自己找找。

#include <iostream>
#include <windows.h>
using namespace std;
class Shape
{
public:
    Shape(){};
    ~Shape(){};
    virtual float GetArea()
    {
        return -1;
    }
};
class Circle:public Shape
{
public:
    Circle(float radius):isRadius(radius){};
    ~Circle(){};
    virtual float GetArea()
    {
        return (3.14*isRadius*isRadius);
    }
private:
    float isRadius;
};
class Rectangle1:public Shape
{
public:                       //类的默认访问权限是私有 故改为共有权限

    Rectangle1(float len,float idth):islenght(len),iswidth(idth){}  // 函数的后面为什么加分号
    ~Rectangle1(){}
    virtual float GetArea()
    {
        return islenght*iswidth;
    }
    float getlenght()
    {
        return islenght;
    }
    float getwidth()
    {
        return iswidth;
    }

    float islenght;
    float iswidth;
};
class Square:public Rectangle1  // 派生类不能访问继承类的私有成员
{
public:
    Square(float len);
    ~Square(){}
};
Square::Square(float len):Rectangle1(len,len)
{

}

int main( )
{
    Shape *sp;
    sp=new Circle(5);
    printf("圆的面积为%f\n",sp->GetArea());
    delete sp;
    sp=new Rectangle1(4,6);
    printf("矩形的面积为:%f\n",sp->GetArea());
    delete sp;
    sp=new Square(5);   
    printf("正方形的面积是:%f\n",sp->GetArea());
    delete sp;
    system("pause");
    return 0;
}

回去仔细看书去！！！！

谢谢你哦，我的每个问题都是你解答出来的，嘿嘿。现在还没有书，等有书了，我一定好好看。再次谢谢。