Null pointer access class member function

// null pointer access class member function

. 1 #include <the iostream>
 2 #include < String >
 . 3  the using  namespace STD;
 . 4  
. 5  class the Person
 . 6  {
 . 7  public :
 . 8      void showInfo ()
 . 9      {
 10          COUT << " null pointer successful access member functions " << endl;
 . 11      }
 12 is  
13 is      void showinfo1 ()
 14      {
 15          COUT Age << << endl;
 16      }
 . 17  
18 is      void showinfo2()
19     {
20         cout << this->age << endl;
21     }
22 
23     void showinfo3()
24     {
25         if (this==NULL)
26         {
27             return;
28         }
29         cout << this->age << endl;
30     }
31         
32 private:
33     int age;
34 };
35 
36 intmain ()
 37 [  {
 38 is      the Person * P = NULL;
 39      p-> showInfo ();
 40      // p-> showinfo1 (); error null pointer
 41 is      // p-> showinfo2 (); error null pointer 
42 is      p-> showinfo3 (); // Analyzing nulls diet, enhanced the code robustness, no error 
43 is  
44 is      System ( " PAUSE " );
 45      return  0 ;
 46 is }