Pointer Concept

Let Us have something which is quite interesting, but many students are scared of and afraid of doing.
YES YES you are getting it right, I am Posting one of the most interesting Post which will make a word like “POINTER” Very much easy in compare to other feature of C Language. With This post i will make you understand the following things

1. Pointer variable
2. Pointer of pointer (double pointer that stores the address of another pointer variable)

#include <stdio.h>
int main()
{

int a=10, *p,**q;
p=&a;
q=&p;
clrscr();
printf("\na=%d *p=%d **q=%d", a, *p, **q);// all prints 10
printf("\n&a=%d p=%d *q=%d", &a, p, *q);
// all prints address of a - 1000
printf("\n &p=%d q=%d", &p, q); // prints address of p - 2000
printf("\n &q=%d", &q); // prints address of q
printf("\na=%d &a=%d", a, &a); // value of a and its address
printf("\n*p=%d p=%d &p=%d", *p, p, &p);
//*p means value at address 1000 p means value of p.
printf("\n**q=%d *q=%d q=%d &q=%d", **q, *q, q, &q);
//**q means value at address of 1000
//E.g.
// &p- address of Variable
// p - value of variable
// *p - value at address that variable preserved
// **p- value at address of address
return 0;
}
output: (as per above figure)
a=10 *p=10 **q=10
&a=1000 p=1000 *q=1000
&p=2000 q=2000
&q=3000
a=10 &a=1000
*p=10 p=1000 &p=2000
**q=10 *q=1000 q=2000 &q=3000

If you have any query or suggestion regarding pointer please comment for the above post, we will be glad to see a comment and will try to solve your query as soon as possible.