C/C++ Puzzles: PART - 25

Peculiar behavior of Arrays

Consider the program given below. The program prints the array elements in different ways. How is it possible? 

#include<stdio.h>

int main( )
{
    int a[ ]={1,2,3,4,5};
    int i;
    for(i=0;i<5;i++)
   {
       printf("\n%d\t%d\t%d\t%d\n",a[i],i[a],*(a+i),*(i+a));
   }
   return 0;
}

Click here to download the C Program.

Figure Below Shows the Output

Explanation:-

  The content of an array a[i] is calculated as follows. *(Starting Address  + Array Index ), where a is the starting address and i is the array index. Since addition is a commutative operation a+b and b+a are the same, so a[i], i[a], *(a+i) and *(i+a) all returns the i^th element of the array a.