实验三

4-11
#include<iostream>
using namespace std;
class area
{
	public:
		area(int len,int wid);//构造函数 
		area(area &s);//复制构造函数 
		int geta(){return a;}
		int getb(){return b;}
		~area();
	private:
		int a,b;
};
//成员函数定义 
area::area(int len,int wid) 
{
	a=len;
	b=wid;
	cout<<"面积为"<<a*b<<endl; 
}
area::area(area &s)
{
	a=s.a;
	b=s.b;
}
area::~area()
{
	 cout <<"释放内存"<< endl;
}
int main()
{
	area(2,3);
	return 0;
}#include<iostream>
using namespace std;
class area
{
	public:
		area(int len,int wid);//构造函数 
		area(area &s);//复制构造函数 
		int geta(){return a;}
		int getb(){return b;}
		~area();
	private:
		int a,b;
};
//成员函数定义 
area::area(int len,int wid) 
{
	a=len;
	b=wid;
	cout<<"面积为"<<a*b<<endl; 
}
area::area(area &s)
{
	a=s.a;
	b=s.b;
}
area::~area()
{
	 cout <<"释放内存"<< endl;
}
int main()
{
	area(2,3);
	return 0;
}
运行结果：(此处长宽为3，2)

 

 

4-20
#include<iostream> 
using namespace std;
class complex
{
	public:
		//构造函数 
		complex(){real=0;imag=0;}
		complex(double r,double i){real=r;imag=i;}
		complex operator+(const complex &c1);
		double getreal(){return real;}
		double getimag(){return imag;}
		~complex();
		void show();
	private:
		double real;
		double imag;
};
complex complex::operator+(const complex &c1)
{
 complex c;
 c.real = real + c1.real;
 c.imag = imag + c1.imag;
 return c;
}
complex::~complex()
{
	cout<<"释放内存"<<endl; 
}
void complex::show()
{
	cout<<"("<<real<<","<<imag<<"i)"<<endl;
}
int main()
{
	complex c1(3,5),c2(4.5,0),c3;
	c3=c1+c2;
	c3.show() ;
	return 0;
} 

　　

（不懂为什么冒出来4个释放内存，析构函数不是在函数最后运行一次吗）

还是得多看看代码，自己勤加练习。
个人觉得，类和对象在使用上和定义一个函数很像，编码思路可以相互靠近。