Question

C++编程：用面向对象的方法求矩形面积. 要求编写一个矩形Rectangle类

用面向对象的方法求矩形面积. 要求编写一个矩形Rectangle类,数据成员有:长（Length)、
宽(Width),函数成员有:(1)构造函数,功能是给长和宽初始化 (2)成员函数setLW(), 功能是给长和宽赋值
(3)成员函数Area()，功能是求出矩形的面积。在main函数中声明该类的对象，求出该对象的面积。

Answer 1

#include<iostream>
using namespace std;
class Retangle
{
public:
Retangle()
{
Length=0;
Width=0;
}
void setLW()
{
float x,y;
cout<<"input the length and width:"<<endl;
cin>>x>>y;
Length=x;
Width=y;
}
void Area()
{
cout<<"Area="<<Length*Width<<endl;
}
private:
float Length;
float Width;
};
void main()
{
Retangle abc;
abc.setLW();
abc.Area();
}

Answer 2

#include<iostream>
using namespace std;
class graph
{
protected:
float high,wide;
public:
graph();
graph(float h,float w)
{
high=h;wide=w;cout<<"高为："<<h<<"\t宽为："<<w<<endl;} };

class retangle:public graph
{
public:
retangle(float h,float w):graph(h,w){}
void area()
{ cout<<"矩形的面积是:"<<high*wide<<endl;}
};

class triangle:public graph
{
public:
triangle(float h,float w):graph(h,w){}
void area()
{ cout<<"等腰三角形的面积是:"<<high*wide/2<<endl;}
};

void main()
{ retangle g(2,3);
g.area();
triangle h(2,3);
h.area();
}

Answer 3

#include<iostream>
using
namespace
std;
class
Retangle
{
public:
Retangle()
{
Length=0;
Width=0;
}
void
setLW()
{
float
x,y;
cout<<"input
the
length
and
width:"<<endl;
cin>>x>>y;
Length=x;
Width=y;
}
void
Area()
{
cout<<"Area="<<Length*Width<<endl;
}
private:
float
Length;
float
Width;
};
void
main()
{
Retangle
abc;
abc.setLW();
abc.Area();
}