ex020205.cpp

来自「深入浅出Visual C++入门进阶与应用实例 随书光盘 作者 何志丹」· C++ 代码 · 共 67 行

// Ex020205.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "memory.h"
#define NULL	((int *)0)

class CData 
{
public:
	CData(int iLeng);//普通构造函数
	CData(){ m_iLeng = 0 ; m_pData = NULL ;};
	~CData();//析构函数
	CData(const CData& other);//拷备构造函数
	CData& operator =(const CData &other);//赋值函数
private:
	int m_iLeng; //动态数组长度
	int * m_pData ;//动态数组
};

int main(int argc, char* argv[])
{
	CData data1(3) ,data4(4);	

	CData data2(data1);//拷备构造函数
	CData data3 = data1 ;//拷备构造函数
	data4 = data1 ; //赋值运算符
	
	return 0;
}

CData::CData(int iLeng)
{
	m_iLeng  = iLeng ;
	m_pData = new int[m_iLeng] ;
}

CData::~CData()
{
	delete [] m_pData ;
}

CData::CData(const CData &other)
{
	m_iLeng = other.m_iLeng ;
	m_pData = new int[m_iLeng];
	memcpy(m_pData,other.m_pData,m_iLeng*sizeof(int));
}

CData& CData::operator =(const CData &other)
{
	//检查自赋值
	if(this == &other)
		return *this ;
	
	//释放原有的内存资源
	delete [] m_pData ;

	//分配内存并复制内容
	m_iLeng = other.m_iLeng ;
	m_pData = new int[m_iLeng];
	memcpy(m_pData,other.m_pData,m_iLeng*sizeof(int));

	//返回本对象的引用
	return *this ;
}