Yeah that's pretty much the key point - that return type of invoking the / method of integer and passing it a decimal is a decimal type cast.
On Jul 12, 12:45 pm, Dave Aronson <googlegroups2d...@davearonson.com> wrote: > On Thu, Jul 12, 2012 at 1:13 AM, John Merlino <stoici...@aol.com> wrote: > > (@objects.size / 3.0).ceil > > > So if size returns 2, then the above expression returns 1. > > > Here's my question. In terms of arithmetic, I dont understand why 3.0 must > > be used and not just 3. > > To clarify (and expand, thus re-muddying) the preceding answers somewhat: > > If a mathematical expression is written with only integers, most > languages will assume that you want an integer answer. How it will > deal with the remainder may vary, such as rounding, truncation, or > "banker's rounding". (IIRC VB or some such thing uses that. The > difference from normal rounding is that normally halves round up, > while in banker's rounding, halves round to whichever way gives an > even number.) > > So, you use .0 to turn one of those integers into a floating point number. > > You can achieve the same thing with a multiplication by 1.0. You'll > see this used where the numbers are variables rather than literals, > especially in languages that make you declare a variable's type, and > distinguish between integers and floating point numbers. > > Either way, in a complicated expression, you may need to be careful > about *which* literal you tack .0 onto, or *when* you multiply by 1.0. > Getting that wrong may wind up with some deeper parts of the > expression yielding integer results, when you really wanted a float. > > -Dave > > -- > Dave Aronson, Cleared/Remote Ruby on Rails Freelancer > (NoVa/DC/Remote); seewww.DaveAronson.com, and blogs > atwww.Codosaur.us,www.Dare2XL.com,www.RecruitingRants.com -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en-US.
