简单模仿string类的设计实现.

#include<iostream>#include<stdio.h>using namespace std;class String{public:char* get(){return m_data;}String(const char *str=NULL);String(const String& other);~String();String& operator=(const String& other);private:char *m_data;};String::String(const char* str){cout<<"构造函数被调用了"<<endl;if(str==NULL){m_data=new char[1];*m_data='/0';}else{int length=strlen(str);m_data=new char[length+1];strcpy(m_data,str);}}String::~String(){delete m_data;cout<<"析构函数被调用了"<<endl;}String::String(const String& other){cout<<"复制构造函数被调用了"<<endl;int length=strlen(other.m_data);m_data=new char[length+1];strcpy(m_data,other.m_data);}String& String::operator=(const String& other){cout<<"赋值函数被调用了"<<endl;if(this==&other)return *this;delete m_data;int length=strlen(other.m_data);m_data=new char[length+1];strcpy(m_data,other.m_data);return *this;}void main(){String b;cout<<b.get()<<endl;String a("Hello");cout<<a.get()<<endl;String c("World");cout<<c.get()<<endl;String d=a;cout<<d.get()<<endl;d=c;cout<<d.get()<<endl;}

也算个经典问题吧.