Explain Arithmetic operations using pointers in C language?

Pointer is a variable which stores the address of other variable.

Pointer declaration, initialization and accessing

Consider the following statement −

int qty = 179;

Declaring a pointer

int *p;

‘p’ is a pointer variable that holds the address of another integer variable.

Initialization of a pointer

Address operator (&) is used to initialize a pointer variable.

int qty = 175; int *p; p= &qty;

Arithmetic operations using pointers

Pointer variables can be used in expressions. For example, if pointer variables are properly declared and initialized then the following statements are valid.

a) *p1 + *p2 b) *p1- *p2 c) *p1 * *p2 d) *p1/ *p2 Note: There must be a blank space between / and * otherwise it is treated as beginning of comment line e ) p1 + 4 f) p2 - 2 g) p1 - p2 Note: returns the no. of elements in between p1 and p2 if both of them point to same array h) p1++ i) – – p2 j) sum + = *p2 j) p1 > p2 k) p1 = = p2 l) p1 ! = p2 Note: Comparisons can be used meaningfully in handling arrays and strings

The following statements are invalid −

a) p1 + p2 b) p1 * p2 c) p1 / p2 d) p1 / 3

Program

#include<stdio.h> main (){    int a,b,x,y,z;    int *p1, *p2;    a =12;    b = 4;    p1= &a;    p2 = &b;    x = *p1 * * p2 – 6;    y= 4 - *p2 / *p1+10;    printf (“Address of a = %d”, p1);    printf (“Address of b = %d”, p2);    printf (“a= %d b =%d”, a,b);    printf (“x= %d y =%d”, x,y); }

Output

Address of a = 1234 Address of b = 5678 a = 12 b= 4 x = 42 y= 14

Explanation