c15_09.cpp

来自「it can help you use C++ program we」· C++ 代码 · 共 66 行

// 重载赋值运算符=，重载函数中预防自复制的代码
#include <iostream >
#include <string>
using namespace std;

class CCat
{
public:
	CCat();								//缺省构造函数
	int GetAge() const { return *m_age; }
	char *GetName() const { return m_name; }
	void SetAge(int age) { *m_age = age; }
	void SetName(char *name);
	CCat operator=(const CCat &);		//重载赋值运算符
private:
	int *m_age;
	char *m_name;
};

CCat::CCat()
{
	m_age = new int;					//给指针分配空间
	*m_age = 5;
	m_name = new char[20];				//给Name指针分配空间
	strcpy(m_name, "Mypet");
}

void CCat::SetName(char *name)
{
	delete []m_name;
	m_name = new char[strlen(name)+1];
	strcpy(m_name, name);
}

CCat CCat::operator=(const CCat & sCat)
{
	//如果源对象的地址和this指针相等，说明它们是同一个对象，是自赋值
	if (this == &sCat) 
		return *this;
	delete []m_name;								//删除原有的空间
	m_name = new char[strlen(sCat.m_name)+1];	//分配新的存储空间
	*m_age = sCat.GetAge();
	strcpy(m_name, sCat.m_name);					//将源对象的值赋给当前对象
	return *this;									//返回当前对象
}

int main()
{
	CCat cat1;
	cat1.SetAge(2);
	cout<< "cat1的年龄是: "<<cat1.GetAge()<< endl
		<< "        昵称："<<cat1.GetName()<<endl;

	CCat cat2;
	cat2.SetName("SunFlower");
	cout<< "cat2的年龄是: "<<cat2.GetAge()<< endl
		<< "        昵称："<<cat2.GetName()<<endl;

	cout<< "\n把cat1的值赋给cat2...\n\n";
	cat2 = cat1;
	cout<< "cat2的年龄是: " << cat2.GetAge() << endl
		<< "        昵称："<<cat1.GetName()<<endl;

	return 0;
}