C + + String class (construction, copy construction, assignment operator overloading, and destructor)

Class String

{

Public

Common constructors

String (const char *STR = NULL)

{

if (str = = NULL)

{

m_data = new Char[1];

*m_data = ' + ';

}

Else

{

m_data = new Char[strlen (str) + 1];

strcpy (m_data, str);

}

}

Copy constructor

String (const string &s)

{

m_data = new Char[strlen (s) + 1];

strcpy (M_data, s.m_data);

}

Assignment operator overloading

String & operator= (const string &s)

{

if (this = = &s)

{

return *this;

}

delete [] m_data;

m_data = new Char[strlen (s.m_data) + 1];

strcpy (M_data, s.m_data);

return *this;

}

Destructors

~string ()

{

if (m_data! = NULL)

{

delete [] m_data;

m_data = NULL;

}

}

Private

Char *m_data;

}

For assignment operator overloading there are three points to note:

The return value should be a reference to increase efficiency, or the return value will generate a temporary copy.

Second, the parameters should be applied, for a reason.

The parameter is set to the const type, preventing parameters from being modified inside the function.

C + + String class (construction, copy construction, assignment operator overloading, and destructor)