Difference between (*++argv)[0] and while(c = *++argv[0])

Question

I have the following snippet of code:

int main(int argc, char *argv[])
{   

     char line[MAXLINE];
     long lineno = 0;
     int c, except = 0, number =          


        

Answer 1

The parentheses change the order in which the expressions are evaluated.

Without parentheses *++argv[0]:

1. argv[0] gets the pointer to character data currently pointed to by argv.
2. ++ increments that pointer to the next character in the character array.
3. * gets the character.

with parentheses (*++argv)[0]:

1. ++argv increments the argv pointer to point to the next argument.
2. * defereferences it to obtain a pointer to the character data.
3. [0] gets the first character in the character array.