Question

What are register variables? What are the advantages of using register variables?

Answer 1

If a variable is declared with a register storage class,it is known as register variable.The
register variable is stored in the cpu register instead of main memory.Frequently used variables
are declared as register variable as it’s access time is faster.

Answer 2

Yes as explained by Vikas it is right some more point i want to add
1.we can not access address of register variable as register don't have any address.
2.We can't use this also in global scope.