variable declaration

[Roy Smith]

In article <MSGID_2=3A5025=2F3.131_4204c40a at fidonet.org>,
 Alexander_Zatvornitskiy at p131.f3.n5025.z2.fidonet.org (Alexander 
 Zatvornitskiy) wrote:

> And, one more question: do you think code like this:
> 
> var S=0
> var eps
> 
> for eps in xrange(10):
>   S=S+ups
> 
> is very bad? Please explain your answer:)

Let me answer that by way of counter-example.

Yesterday I was writing a little perl script.  I always use "use strict" in 
perl, which forces me to declare my variables.  Unfortunately, my code was 
giving me the wrong answer, even though the interpreter wasn't giving me 
any error messages.

After a while of head-scratching, it turned out that I had written "$sum{x} 
+= $y" instead of "$sum{$x} += $y".  The need to declare variables didn't 
find the problem.  I *still* needed to test my work.  Given that I needed 
to write tests anyway, the crutch of having to declare my variables really 
didn't do me any good.