#include <stdlib.h>
class String{
private:
	char *pch;    //Pointer to a CHar array
	int length;
	static char nul;
public:
	String();
	String(char *p);
	String(String const &s);
	~String();
	bool operator == (String s2) const;
	String operator = (String &s);
	String operator + (String &s) const;

	//friend ostream& operator << (ostream &os, String &s);
	//friend istream& operator >> (istream &is, String &s); - I would put these in string.cpp but the compiler complains about not being able to access pch
	
	friend ostream& operator << (ostream &os, String &s)
	{
		os << s.pch;
		return os;
	}
	friend istream& operator >> (istream &is, String &s)
	{
		if(s.pch != &String::nul) delete[] s.pch;
		char *ptemp = new char[1000];
		is.getline(ptemp, 1000, '\n');
		s.length = strlen(ptemp);
		s.pch = new char [s.length +1];
		strcpy(s.pch, ptemp);
		return is;
	}			
};

#include <iostream>
#include <stdlib.h>
using namespace std;
#include "String.h"
char String::nul = '\0';

//default constructor
String::String()
{
	pch = 0;
	length = 0;
}

String::String(char *p)
{
	if( p == 0 ){abort();}
	length = strlen(p);
	pch = (char*) malloc(length+1);
	strcpy(pch, p);
}

//copy constructor
String::String(String const &str)
{
	if (str.pch==0){
		pch = 0;
		length = 0;
	} else{
		length = str.length;
		pch = (char*) malloc(length+1);
		strcpy(pch, str.pch);
		}
}

//destructor
String::~String()
{
	delete[] pch;
}

//overloaded '=='
bool String::operator == (String s2) const
{	
	if ( strcmp(pch, s2.pch) == 0 ) return true;
	else{
		return false;
		}
}

String String::operator = (String &s) 
{
	String temp (s.pch);
	if (s.length > length) {delete [] pch;} //free old memory
	pch = new char[s.length];
	length = s.length;
	}
	strcpy (pch, s.pch);
        strcpy (temp.pch, s.pch);
	return temp;
}
//overloaded '+'
String String::operator + (String &s) const
{
	String temp;
	temp.length = length + s.length;
	if(temp.length == 0) return temp;
	temp.pch = new char[temp.length +1];
	strcpy(temp.pch, pch);
	strcat(temp.pch, s.pch);
	return temp;
}

#include <iostream>
#include "String.h"
using namespace std;

int main()
{
	String s1, s3;	
	String s2("This is a String");		
	cout << "Input a String: " << endl;
	cin >> s1;
	s1 = s2;
	if (s1 == s2)
	{
		cout << "s1 is equal to s2" << endl;
	}
	s3 = s1 + s2;
	cout << s3 << " = " <<s1 << " + " << s2 << endl;
	return 0;
}