Rewrite of the String class

Header file String.h

Class String
{
Public
String ();
String (char *str);

~string ();
String (const string &other);

String & operator = (const string &other); Assignment function
Friend string operator + (const string &S1, const string &s2);

void display (void);

Private
Char *m_data;
int Len;
};

Implementing File String.cpp
#include "String.h"
#include <iostream.h>
#include <string.h>

String::string ()
{
cout << "No parameter constructor is called" << Endl;

len = 0;
m_data = new Char[1];
M_data[0] = '/0 ';
}

String::string (char *str)
{
cout << "with parameter constructor called" << Endl;

len = strlen (str);
m_data = new Char[len + 1];
strcpy (m_data, str);
}

string::string (const String &other)
{
cout << "Copy constructor is called" << Endl;

len = Other.len;
m_data = new Char[len + 1];

strcpy (M_data, other.m_data);
}

String & string::operator = (const String &other)//Assignment function
{
cout << "overloading = function is called" << Endl;

if (this = = &other)
{
return *this;
}

delete [] m_data;

len = Other.len;
m_data = new Char [len + 1];
strcpy (M_data, other.m_data);

return *this;

}

String::~string ()
{
cout << "destructor is called" << Endl;
delete [] m_data;
}

void String::d isplay ()
{
cout << "M_data=" << m_data << "len =" << len << Endl;
}

String operator + (const string &S1, const string &s2)
{
cout << "overloaded + functions are called" << Endl;

String temp;

Delete Temp.m_data;

Temp.len = S1.len + S2.len;
Temp.m_data = new Char [Temp.len + 1];

strcpy (Temp.m_data, s1.m_data);
strcat (Temp.m_data, s2.m_data);

return temp;
}

Main.cpp

#include "String.h"
#include <iostream.h>

int main (void)
{
String A;
String B ("Hello");
String C (b);
String d ("Ni Hao");
String e;

A.display ();
B.display ();
C.display ();
D.display ();
E.display ();

cout << Endl;

A = D;
A.display ();

cout << Endl;

E = b + D;
cout << "Here" <<endl;
E.display ();

cout << Endl;

return 0;
}