What is token passing operator ?

The ## operator is known as token passing operator. It allow us to joint two tokens within a macro definition to form a single token i.e. it concatenated two tokens into one token.

Ex:

#define JOIN(A1,A2) A1 ## A2

void main()

{

     ……………………..

     ………………………..

     printf(“%d\n”,JOIN(X,Y));

     ………………….

     ………………………..

}