c++类实现

大部分已经实现，小部分大同小异

因为上课还没上到运算符重载，以前写优先队列之类的都是friend重载，今天意外的发现有些不能用friend那个样子重载。

/**************
大概的已经完成了
***************/
#include <cstdio>
#include <cstring>
#include <iostream>
using namespace std;
/*int main(){
    char s1[]="abc";
    char s2[100];
    strcpy(s2,s1);
    printf("%s",s2);
}
*/
class   STRING{
public:
    STRING(const char* p=NULL){
        if(p==NULL){
           data = new char[100];
           *data = '\0';
           Size=0;
        }
        else{
           Size = strlen(p);
           data = new char[Size+1];    
           strcpy(data,p);
        }
    }
    void operator = (const STRING& S1){
        strcpy(data,S1.data);
        return;
    }
    bool operator == (const STRING& s1){
        return strcmp(data,s1.data);
    }
    friend ostream& operator << (ostream& out, const STRING& str){
        out<<str.data;
        return out;
    }
     friend istream& operator >> (istream& in, const STRING& str){
        in>>str.data;
        return in;
    }
    ~STRING(void){
        if(data != NULL){
            delete[] data;
        }
    }
    int operator [](int x){
        return *(data+x);
    }
private:
    char *data;
    int Size;
};
int main(){
    STRING S1="hello";
    cin>>S1;
    cout<<S1;
}