Give an example of pointer addition and subtraction in C

Pointers have many simple concepts that are very important for C programming.

The following explains two pointer arithmetic concepts, namely C pointer addition and subtraction.

C pointer addition

C pointer addition refers to adding a value to a pointer variable.

The formula is as follows −

new_address= current_address + (number * size_of(data type))

Example

The following is a C program for C pointer addition:

Demonstration

#include<stdio.h>
int main(){
   int num=500;
   int *ptr;//pointer to int
   ptr=#//stores the address of number variable
   printf("add of ptr is %u </p><p>",ptr);
   ptr=ptr+7; //adding 7 to pointer variable
   printf("after adding add of ptr is %u </p><p>",ptr);
   return 0;
}

Output

When the above program is executed, it produces the following result −

add of ptr is 6422036
after adding add of ptr is 6422064

C pointer subtraction

It subtracts a value from a pointer variable. Subtracting any number from a pointer variable results in an address.

The formula is as follows −

new_address= current_address - (number * size_of(data type))

Example

The following is a C program for C pointer subtraction

Real-time demonstration

#include<stdio.h>
int main(){
   int num=500;
   int *ptr;//pointer to int
   ptr=#//stores the address of number variable
   printf("addr of ptr is %u </p><p>",ptr);
   ptr=ptr-5; //subtract 5 to pointer variable
   printf("after sub Addr of ptr is %u </p><p>",ptr);
   return 0;
}

Output

When the above program is executed, it produces the following results −

addr of ptr is 6422036
after sub Addr of ptr is 6422016

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