What does sizeof (function(argument)) return?

Question

What will be the output of program

#include 

int fun(char *a){
    printf(\"%d\\n\",sizeof(a));
    return 1;
}

int main(){
    char a[20];
         


        

Answer 1

keyword sizeof followed by ellipsis returns the number of elements in a parameter pack.

The type of the result is the unsigned integral type size_t defined in the header file