~cpp
#include <iostream>  
#include <cstring>  
#include <cstdlib>  
using namespace std;  

class newstring  
{  
public:  
    char * ch;  
public:  

    newstring::newstring()  
    {  
        ch = '\0';  
    }  
    explicit newstring::newstring(int num) 
    { 
        ch = new char[num]; 
        for(int i =0; i < num; i++) 
            ch[i] = '\0'; 
    } 

	newstring::~newstring()  
    {  
        delete [] ch;  
    }  
      
    int newstring::length() const  
    {  
        return strlen(ch);  
    }  
      
    newstring::newstring(const char* ch)  
    {  
        this->ch = new char[strlen(ch)+1]; 
        strcpy(this->ch,ch); 
    } 

    newstring::newstring(const newstring & ns) 
    { 
        ch = new char[strlen(ns.ch)+1]; 
        strcpy(ch,ns.ch); 
    }     
    
    operator char*()
	{
        return ch; 
    }

    void operator+=(const newstring & a) 
    { 
        char * temp = new char[strlen(ch)+strlen(a.ch)+1]; 
        strcpy(temp,ch); 
         
        strcpy(temp+strlen(ch),a.ch); 
        delete [] ch; 
        ch = temp; 
    } 
	
	
/* 
    newstring & newstring::operator=(const char* ch)  
    {  
        if(this->ch == ch) 
            return *this; 
        delete [] this->ch; 
        this->ch = new char[strlen(ch)+1]; 
        strcpy(this->ch, ch); 
        return *this; 
    }  
*/ 
    newstring & newstring::operator=(const newstring ns)  
    {  
        if(this->ch == ns.ch)  
            return *this;  
        delete [] this->ch;  
        ch = new char[strlen(ns.ch)+1];  
        strcpy(this->ch, ns.ch);
		return *this;
    } 
}; 

bool operator==(const newstring & a, const newstring & b) 
{ 
    if(strcmp(a.ch,b.ch) == 0) 
        return true; 
    else 
        return false; 
}  

newstring & operator+(const newstring & a, const newstring & b) 
{ 
    newstring *temp = new newstring(strlen(a.ch)+strlen(b.ch)+1); 
    strcpy(temp->ch,a.ch); 
    strcpy(temp->ch+strlen(a.ch),b.ch); 
    return *temp; 
} 

ostream & operator<<(ostream & os, const newstring& ns)  
{  
    os << ns.ch;  
    return os;  
}  

istream & operator>>(istream & is, newstring & ns) 
{ 
    char temp[100]; 
    is >> temp; 
    delete [] ns.ch; 
    ns.ch = new char[strlen(temp)+1]; 
    strcpy(ns.ch,temp); 
    return is; 
} 

int main()  
{  
/*    newstring s = "123"; 
    cout << s << endl; 

    newstring s = "123"; 
    cout << s.length() << endl; 

    const newstring s = "123";  
    cout << s.length() << endl;  

    newstring s1 = "123", s2 = "456"; 
    cout << s1 << s2 << endl; 

    newstring s; 
    cout << "string?"; 
    cin >> s; 
    cout << "input string : " << s << endl; 

    newstring s1 = "123"; 
    newstring s2 = s7; 
    cout << s2; 

    newstring s1 = "123", s2; 
    s2 = s1; 
    cout << s1 << " " << s2 << endl; 

    newstring s1, s2; 
    s1 = "123"; 
    s2 = s1; 
    cout << s1 << " " << s2 << endl; 
     
    newstring s = "12345"; 
    cout << s[2] << endl; 
    s[2] = 'X'; 
    cout << s << endl; 

    newstring s(10); 
    s[0] = 'a'; 
    s[1] = 'A'; 
    s[2] = 'B'; 
    cout << s << endl; 

    newstring s = 10; 
    if(s == 10) 
        cout << "s는 10입니다" << endl; 
    else 
        cout << "s는 10아닙니다" << endl; 
 
     
    newstring s1 = "123", s2 = "456"; 
    cout << s1+s2 << endl; 
    if(s1 == "123") 
        cout << "s1은 123입니다." << endl; 
    s1 += s2; 
    cout << s1 << endl; 
*/
	newstring s;
	s = "123";
	char s2[1024];
	strcpy(s2,s);
	cout << s2 << endl;

    return 0;  
}  

Retrieved from http://wiki.zeropage.org/wiki.php/OurMajorLangIsCAndCPlusPlus/2006.2.06/김상섭
last modified 2021-02-07 05:23:56