赋值构造函数(重载赋值操作符)(c++常问问题二)

class cat
{
public:
	//构造函数
	cat():m_pMyName(NULL),m_unAge(0)
	{
		cout<<"cat defult ctor"<<endl;
	}

	//子类赋值构造函数（重载赋值操作符）
	cat& operator=(cat& other)
	{
		this->m_unAge = other.m_unAge;

		//把自己的空间释放先
		if (0 != this->m_pMyName)
		{
			delete this->m_pMyName;
			this->m_pMyName = NULL;
		}

		//如果目标有名字
		if (other.m_pMyName)
		{
			//动态分配一个名字长度+1的堆..此处为深拷贝
			int len = strlen(other.m_pMyName);
			m_pMyName = new char[len + 1];
			memset(m_pMyName , 0 , len+1);
			memcpy(m_pMyName , other.m_pMyName , len+1);
		}

		/*
		//如果目标有名字
		if (other.m_pMyName)
		{
			//动态分配一个名字长度+1的堆..此处为浅拷贝..只复制了指针，没复制指针指向的对象
			m_pMyName = other.m_pMyName;
		}
		*/
		return *this;
	}

	unsigned int m_unAge;
	char* m_pMyName;
};

//实战演练
void main()
{
    cat A;
    cat B = A; //复制拷贝函数
    cat C(A);//复制拷贝函数
    cat D;
    D = A;//赋值构造
}