2.5: Pointer Arithmatic

Pointer Expressions and Pointer Arithmetic

A limited set of arithmetic operations can be performed on pointers which are:

• incremented ( ++ )
• decremented ( — )
• an integer may be added to a pointer ( + or += )
• an integer may be subtracted from a pointer ( – or -= )
• difference between two pointers (p1-p2)

(Note: Pointer arithmetic is meaningless unless performed on an array.)

// C++ program to illustrate Pointer Arithmetic in C++ 
#include <iostream> 
using namespace std; 

int main() 
{ 
   //Declare an array 
   int v[3] = {10, 100, 200}; 

   //declare pointer variable 
   int *ptr; 

   //Assign the address of v[0] to ptr 
   ptr = v; 

   for (int i = 0; i < 3; i++) 
   { 
      cout << "Value at ptr = " << ptr << "\n"; 
      cout << "Value at *ptr = " << *ptr << "\n"; 

      // Increment pointer ptr by 1 
      ptr++; 
   } 
   
   return 0;
} 

Output:

Value at ptr = 0x7fff9a9e7920

Value at *ptr = 10

Value at ptr = 0x7fff9a9e7924

Value at *ptr = 100

Value at ptr = 0x7fff9a9e7928

Value at *ptr = 200

Adapted from:

"Pointers in C/C++ with Examples" by Abhirav Kariya, Geeks for Geeks is licensed under CC BY 4.0