Re: using params in a comparison

Bobnation
Wed, 28 May 2008 06:22:53 -0000

Wow, thanks a ton for that concise description ... that just saved me
probably an hour of digging in one of my books.

On May 27, 10:04 pm, Robert Walker
<r0b3rt4...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> Just to add a bit of clarity: you should also keep in mind the Ruby
> idioms for object identity vs. object equality. This one still trips
> me up from time-to-time coming from Java to Ruby:
>
> The == and .eql? methods in Ruby compare object equality (typically)
> where as the == operator in Java compares object identity (do these
> variables reference the same object?). Typically .equal? is used to
> compare object identity in Ruby.
>
> ------------------------------------->> s1 = "Rubies are
red"
> >> s2 = "Rubies are red"
> >> s1 == s2    => true
> >> s1.eql? s2    => true
> >> s1.equal? s2    => false
>
> ------------------------------------->> s1 = "Rubies are
red"
> >> s2 = s1
> >> s1 == s2    => true
> >> s1.eql? s2    => true
> >> s1.equal? s2    => true
>
> -------------------------------------
>
> Notice in the first example the two string have the same value (the
> same sequence of characters), but do not have the same identity. In
> the second case both s1 and s2 refer to the same string and do have
> the same identity.
>
> On May 27, 10:04 pm, Dave Lynam
<dly...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>
> > exactly what i was looking for.  thanks.
>
> > On May 27, 6:56 pm, Alex Wayne
<rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>
> > wrote:
>
> > > Dave Lynam wrote:
> > > > Other is a column in the database.  So photo.other is the
value in
> > > > this column and I only want to display the photos where the
> > > > params[:id] matches this photo.other value.
>
> > > > On May 27, 6:29 pm, "Ryan Bigg (Radar)"
<radarliste...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>
> > >   123 == "123" #=> false
>
> > > The params hash contains strings.  A database column stored as an
> > > integer, will return an integer.  And an integer will not equate
to a
> > > string.
>
> > >   photo.other == params[:id].to_i
>
> > > or
>
> > >   photo.other.to_s == params[:id]
> > > --
> > > Posted viahttp://www.ruby-forum.com/.
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