[Edu-sig] Re: easy for beginners, even children

[Terry Hancock]

On Wednesday 14 April 2004 05:54 pm, Daniel Ajoy wrote:
> > But why would they say "set 2 equal to 3" if they want 
to
> > know "is 2 equal to 3"?
> 
> Because 2 = 3 is what they would write on paper.
> 
> But I agree that it does not take much brilliance to
> understand that = and == are different things, and when
> to use each one.

Actually there's a very important lesson there. One thing
that takes some appreciation is that programming (well, 
procedural programming) is *prescriptive*, not 
*descriptive*, which makes it different from, say algebra.

I mean:

x = x + 1

is an extremely common thing to do in programming (so common 
we have a shortcut

x += 1

).

But that's obviously a false statement in algebra.  
Therefore it's really important to point out that we are 
doing two fundamentally different things when we are 
*assigning* a value and when we are *testing* a value.

Even if the syntax let us confuse these two operations (as 
it could -- Python doesn't really need two different 
symbols for these operations since the assignment is 
illegal in tests), it's still a good thing to learn.

Algorithms are fundamentally different from equations, and 
this is a good place for the student to learn something. A 
potential "Aha!" moment, in fact.


--
Terry Hancock ( hancock at anansispaceworks.com )
Anansi Spaceworks  http://www.anansispaceworks.com