Compile string constructor, destructor, and value assignment function

# Include <iostream>

Using namespace STD;

Class string
{
Public:
String (const char * STR = NULL );
String (const string & other );
~ String (void );
String & operator = (const string & other );
Const char * getstring () const;

PRIVATE:
Char * m_data;
};

String ::~ String (void)
{
Delete [] m_data;
}

String: string (const char * Str)
{
If (STR = NULL)
{
M_data = new char [1];
* M_data = '\ 0 ';
}
Else
{
Int length = strlen (STR );
M_data = new char [Length + 1];
Strcpy (m_data, STR );
}
}

String: string (const string & other)
{
Int length = strlen (other. m_data );
M_data = new char [Length + 1];
Strcpy (m_data, other. m_data );
}

String & string: Operator = (const string & other)
{
If (this = & other)
{
Return * this;
}

Delete [] m_data;
Int length = strlen (other. m_data );
M_data = new char [Length + 1];
Strcpy (m_data, other. m_data );

Return * this;
}

Const char * string: getstring () const
{
Return m_data;
}

Int main ()
{
String STR ("hello ");
String str1 ("Meng ");
String str2 (str1 );
String str3 ("Jun .");
String str4 (str3 );
String str5 = str4;

Cout <Str. getstring () <str2.getstring () <str5.getstring () <Endl;

Return 0;
}