constructor with reference (copy constructor)

#include "stdafx.h"

#include <iostream>

#include <string>

using namespace std;

class String

{

private:

char *str;

int len;

public:

String();

String(const char *str);

String(const String &copy);

const char *c_str();

void Release();

};

int main()

{

String str1 = "String";

String str2 = str1;

cout << str1.c_str() << endl;

cout << str2.c_str() << endl;

str1.Release();

str2.Release();

return 0;

}

String::String() 

: str(0), len(0){

str = new char;

*str = 0;

}

String::String(const char *str)

:str(0), len(0)

{

for (len = 0; str[len]; len++);

this->str = new char[len + 1];

for (int i = 0; i < len + 1; i++) {

this->str[i] = str[i];

}

}

const char *String::c_str() { return str; }

void String::Release() {

delete[] str;

return;

}

String::String(const String &copy)

: str(0), len(copy.len)

{

str = new char[len + 1];

for (int i = 0; i < len+1; i++)

{

str[i] = copy.str[i];

}

}