clearing a char array c

Question

I thought by setting the first element to a null would clear the entire contents of a char array.

char my_custom_data[40] = \"Hello!\";
my_custom_data[0] = \         


        

Answer 1

Why not use memset()? That's how to do it.

Setting the first element leaves the rest of the memory untouched, but str functions will treat the data as empty.