C++ LANGUAGE POINTER COMPARISONS

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C++ LANGUAGE POINTER COMPARISONS

Pointer Comparisons 


Pointers may be compared by using relational operators, such as ==, <, 
and >. If p1 and p2 point to variables that are related to each other, 
such as elements of the same array, then p1 and p2 can be meaningfully compared. 

The following program modifies the previous example one by incrementing the 
variable pointer so long as the address to which it points is either less 
than or equal to the address of the last element of the array, which is &var[MAX - 1]: 

#include <iostream> 
 
using namespace std; 
const int MAX = 3; 
 
int main () 
{ 
   int  var[MAX] = {10, 100, 200}; 
   int  *ptr; 
 
   // let us have address of the first element in pointer. 
   ptr = var; 
   int i = 0; 
   while ( ptr <= &var[MAX - 1] ) 
   { 
      cout << "Address of var[" << i << "] = "; 
      cout << ptr << endl; 
 
      cout << "Value of var[" << i << "] = "; 
      cout << *ptr << endl; 
 
      // point to the previous location 
      ptr++; 
      i++; 
   } 
   return 0; 
} 
When the above code is compiled and executed, it produces result something as follows: 
Address of var[0] = 0xbfce42d0 
Value of var[0] = 10 
Address of var[1] = 0xbfce42d4 
Value of var[1] = 100 
Address of var[2] = 0xbfce42d8 
Value of var[2] = 200