3-4 计算长方形的周长和面积
Time Limit: 1000MS Memory limit: 65536K
题目描述
通过本题的练习可以掌握拷贝构造函数的定义和使用方法;
设计一个长方形类Rect,计算长方形的周长与面积。类中有私有数据成员Length(长)、Width(宽),由具有缺省参数值的构造函数对其初始化,函数原型为:Rect(double Length=0, double Width=0); 再为其定义拷贝构造函数,形参为对象的常引用,函数原型为:Rect(const Rect &); 编写主函数,创建Rect对象r1初始化为长、宽数据,利用r1初始化另一个Rect对象r2,分别输出对象的长和宽、周长和面积。
要求: 创建对象 Rect r1(3.0,2.0),r2(r1);
输入
输入两个实数,中间用一个空格间隔;代表长方形的长和宽
输出
共有6行
;
分别输出r1的长和宽;
r1的周长;
r1的面积;r2的长和宽;
r2的周长;
r2的面积;注意单词与单词之间用一个空格间隔
示例输入
56 32
示例输出
the length and width of r1 is:56,32
the perimeter of r1 is:176
the area of r1 is:1792
the length and width of r2 is:56,32
the perimeter of r2 is:176
the area of r2 is:1792
提示
输入 -7.0 -8.0
输出
the length and width of r1 is:0,0
the perimeter of r1 is:0
the area of r1 is:0
the length and width of r2 is:0,0
the perimeter of r2 is:0
the area of r2 is:0
#include <iostream>
using namespace std;
class box
{
private:
double l,w;
public:
box(double=0,double=0);
double s();
double c();
};
box::box(double len,double wide)
{
l=len;
w=wide;
}
double box::s()
{
return l*w;
}
double box::c()
{
return 2*(l+w);
}
int main()
{
double n,m;
cin>>n>>m;
if(n<=0 ||m<=0)
{
cout <<"the length and width of r1 is:0,0"<<endl;
cout <<"the perimeter of r1 is:0"<<endl;
cout <<"the area of r1 is:0"<<endl;
cout <<"the length and width of r2 is:0,0"<<endl;
cout <<"the perimeter of r2 is:0"<<endl;
cout <<"the area of r2 is:0"<<endl;
}
else
{
box box1(n,m);
cout <<"the length and width of r1 is:"<<n<<","<<m<<endl;
cout <<"the perimeter of r1 is:"<<box1.c()<<endl;
cout <<"the area of r1 is:"<<box1.s()<<endl;
box box2(box1);
cout <<"the length and width of r2 is:"<<n<<","<<m<<endl;
cout <<"the perimeter of r2 is:"<<box2.c()<<endl;
cout <<"the area of r2 is:"<<box2.s()<<endl;
}
return 0;
}
#include <iostream>
using namespace std;
class box
{
private:
double l,w;
public:
box(double=0,double=0);
double s();
double c();
};
box::box(double len,double wide)
{
l=len;
w=wide;
}
double box::s()
{
return l*w;
}
double box::c()
{
return 2*(l+w);
}
int main()
{
double n,m;
cin>>n>>m;
if(n<=0 ||m<=0)
{
cout <<"the length and width of r1 is:0,0"<<endl;
cout <<"the perimeter of r1 is:0"<<endl;
cout <<"the area of r1 is:0"<<endl;
cout <<"the length and width of r2 is:0,0"<<endl;
cout <<"the perimeter of r2 is:0"<<endl;
cout <<"the area of r2 is:0"<<endl;
}
else
{
box box1(n,m);
cout <<"the length and width of r1 is:"<<n<<","<<m<<endl;
cout <<"the perimeter of r1 is:"<<box1.c()<<endl;
cout <<"the area of r1 is:"<<box1.s()<<endl;
box box2(box1);
cout <<"the length and width of r2 is:"<<n<<","<<m<<endl;
cout <<"the perimeter of r2 is:"<<box2.c()<<endl;
cout <<"the area of r2 is:"<<box2.s()<<endl;
}
return 0;
}