Re: intro

At 02:52 PM 10/29/99 -0600, Nathan Torkington wrote:
>Peter Scott writes:
> > I'm having a hard time with hashes for beginners.
> >
> > >Do you use analogies and metaphors,
> >
> > Of course...
>
>I draw a two-column table on the whiteboard and say "this is a hash."
>I label the left column "keys" and the right column "values".  Then
>I show the effects of:
>
>   $hash{Nat} = 26;
>   print "$hash{Nat}\n";
>   $hash{Nat} = 32;
>   print "$hash{Nat}\n";

Can I have your students? :-)  I do this, I also draw analogies with 
databases, talk about how a hash is like an array where you get to pick the 
indices, give them a cheat sheet showing the different types of basic 
operations on the primitives with examples, do examples on the computer in 
front of them... and still when they have an exercise involving traversing 
a hash some people sit there starting at the screen and eventually type 
something like @hash{$values} = keys @keys ...



--
Peter Scott
Pacific Systems Design Technologies