C pointer address operator

A. Address Operator in C Programming

In the previous chapter we have learnt about more basic understanding about pointer. In this chapter we will be learning about address operator in C programming.

1. It is Denoted by ‘&’
2. When used as a prefix to a variable name ‘&’ operator gives the address of that variable.

Example :

&n  -  Gives address on n

B. How Address Operator works ?

#include<stdio.h>
void main()
{
int n = 10;
printf("\nValue of n is : %d",n);
printf("\nValue of &n is : %u",&n);
}

Output :

Value of  n is : 10
Value of &n is : 1002

C. Visual Understanding :

Consider the following program -

#include<stdio.h>
int main()
{
int i = 5;
int *ptr;
ptr = &i;
printf("\nAddress of i    : %u",&i);
printf("\nValue of ptr is : %u",ptr);
return(0);
}

After declaration memory map will be like this -

int i = 5;
int *ptr;

after Assigning the address of variable to pointer , i.e after the execution of this statement -

ptr = &i;

D. Invalid Use of Address Operator

• We cannot use Address operator for Accessing Address of Literals.
• Only Variables have Address associated with them.

&75

• (a+b) will evaluate addition of Values present in variables.
• Output of (a+b) is nothing but Literal , so we cannot use Address operator

&(a+b)

• Again ‘a’ is Character Literal, so we cannot use Address operator.

&('a')

E. Conclusion :

Thus we have learnt -

In the next chapter we will be learning Memory Organisation of Pointer Variable.