On Jul 22, 2010, at 13:03, Amy Gibbs wrote: > I've tried declaring all sorts of things trying to get it to work :D float, > decimal, (the entity properties are decimal in the datamodel), NSNumber, but > I still get the error: invalid operands to binary / > > I assume I can't use int as the figures aren't integers, I only need it to 2 > decimal places (for currency).
You're missing the distinction between an object and a scalar value. 'valueForKey' returns an object (presumably a NSNumber), but '/' needs scalars. So, you need something along this line: NSNumber* price = [Product valueForKey:@"UOMcost"]; NSNumber* uom = [Product valueForKey:@"purchaseUOM"]; double result = [uom doubleValue] / [price doubleValue]; NSNumber* cost = [NSNumber numberWithDouble: result]; [Product setValue: cost for Key: ...]; Incidentally, if you're dealing with currency, it's better to use integers (the number of cents, rather than the number of dollars, essentially) rather than floating point. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com