Compile string-like constructor, destructor, and assignment function

C ++Code 

 Class String
{
 Public :
String ( Const   Char * STR = NULL ); //  Common Constructor  
 String ( Const String & other ); //  Copy constructor  
 ~ String ( Void ); //  Destructor  
 String & operate = ( Const String & other ); //  Value assignment function  
  Private :
 Char * M_data; //  Used to save strings  
 };

Compile the preceding four functions of string.

C ++ code

 // Common Constructor  
 String: string ( Const   Char * Str)
{
 If (STR = NULL)
{
M_data = New   Char [ 1 ]; //  Score point: automatically apply to store the ending sign '\ 0' for an empty string  //  Extra points: determines if m_data is added with null 
 * 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 );
}
}
 //  String destructor  
 String ::~ String ( Void )
{
Delete [] m_data; //  Or delete m_data;  
 }
 //  Copy constructor  
 String: string ( Const String & other) //  Score point: the input parameter is of the const type.  
 {
 Int Length = strlen (other. m_data );
M_data = New   Char [Length + 1 ]; //  Extra points: determines if m_data is added with null  
 Strcpy (m_data, other. m_data );
}
 // Value assignment function  
 String & string: operate = ( Const String & other) //  Score point: the input parameter is of the const type.  
 {
 If ( This ==& Other) //  Score point: Check auto-assigned values  
                  Return * This ;
Delete [] m_data; //  Score point: Release original memory resources  
          Int Length = strlen (other. m_data );
M_data = New   Char [Length + 1 ]; //  Extra points: determines if m_data is added with null  
 Strcpy (m_data, other. m_data );
 Return * This ; //  Score point: returns the reference of this object.  
 
}

Analysis:

The interviewer who can accurately compile string class constructor, copy constructor, assign value function and destructor has at least 60% of the basic C ++ skills! This class includes the pointer class member variable m_data,When a class includes pointer class member variables, it must be overloaded to copy constructors, assign values, and destructor.ProgramBasic RequirementsIt is also a special clause in Objective C ++. Take a closer look at this class and pay special attention to the significance of adding comments to the score points and points. In this way, more than 60% of the basic C ++ skills are available!