#include
#include #strcpy
using namespace std;
class String{
public:
String(const char* str = NULL):
m_str(strcpy(new char[strlen(str?str:"")+1],
str?str:"")){}
~String(){
if(m_str){
delete [] m_str;
m_str = NULL;
}
}
//拷贝构造
String(const String& that):
m_str(strcpy(new char[strlen(that.m_str)+1],that.m_str)){}
//拷贝赋值,成员变量m_str为指针为指针时,要注意深拷贝,这里为深拷贝
String& operator=(const String& that){
if(&that != this){
char* = new char[strlen(that.m_str)+1];
delete[] m_str;//先释放旧资源
m_str = strcpy(str,that.m_str);
}
return *this;
}
friend ostream& operator<<(ostream& os,const String&c){
os << c.m_str;
return os;
}
//c接口
const char* c_str(void)const{
return m_str;
}
public:
char* m_str;
};
int main(void){
String s1("hello,world");
cout << s1 << endl;
return 0;
}
本文标题:当类的成员变量为字符串的时候,注意深拷贝
文章出自:
http://chengdu.cdxwcx.cn/article/gjdjid.html