Constructors of the string class

Compile the constructor, destructor, and value assignment functions of the string class. The prototype of the known string class is:
Class string
{
Public:
String (const char * STR = NULL); // common Constructor
String (const string & other); // copy the constructor
~ String (void); // destructor
String & operate = (const string & other); // value assignment function
PRIVATE:
Char * m_data; // used to save strings
};

 

 //  String Constructor String: string ( Const   Char * Str) //  6 points  {  If (STR = Null) {m_data = New   Char [ 1 ]; //  It is better if null can be added. * M_data = '\ 0  ';}  Else  {  Int Length = Strlen (STR); m_data = New   Char [Length +1 ]; //  It is better if null can be added.  Strcpy (m_data, STR );}}


  //  Copy constructor String: string ( Const String & other)
 {  Int Length = Strlen (other. m_data); m_data = New   Char [Length + 1 ];//  It is better if null can be added.  Strcpy (m_data, other. m_data );}


  //  Value assignment function String & string: operate = ( Const String & other)
 {  //  (1) Check auto-assigned values
    If ( This == & Other)  Return *This  ;  //  (2) Release original memory resources
  Delete [] m_data;  //  (3) allocate new memory resources and copy the content
    Int Length = Strlen (other. m_data); m_data = New   Char [Length + 1 ]; //  It is better if null can be added. Strcpy (m_data, other. m_data );  //  (4) return the reference of this object
    Return * This  ;} 

//String destructor
String ::~ String (Void){
Delete [] m_data;
//Because m_data is an internal data type, you can also write it as delete m_data;
}

The C standard library contains the string Library: String. h contains strlen (), strcpy () functions, and so on.

C-style string library in C ++: # include <cstring>

Extended string library in C ++: # include <string>