On Sun, Apr 20, 2014 at 01:53:33PM +0200, Alexander Huemer wrote: > Hi, > > On Sun, Apr 20, 2014 at 03:41:40PM +0400, non...@inventati.org wrote: > > […] > > -#define LEN(a) (sizeof(a) / sizeof(a[0])) > > +#define LEN(a) (sizeof(a) / sizeof(a)[0]) > > […] > > Why parenthesis anyway? a[0] is an expression, not a type, and there is > nothing to group here. sizeof is not a function!
Because it is a macro and there can be another expression (such as m+1 where m is an array). Macro would expand to (sizeof(m+1) / sizeof(m+1[0])) instead of (sizeof(m+1) / sizeof(m+1)[0])