[Tutor] Program for outputing the letter backward

John Fouhy john at fouhy.net
Wed Mar 29 08:10:02 CEST 2006


On 29/03/06, Hoffmann <oasf2004 at yahoo.com> wrote:
> Hi John,
>
> (1) vehicle[index] is: 'c'
> (2) If index = index = 1, so vehicle[index] becomes:
> 'a'

What I'm getting at here is that, by changing index, we can change
which letter we are looking at.  And index is a number, which means
it's easier to reason about than letters are.

Let's have a look at a possible solution:

>>> vehicle = 'car'
>>> index = 2
>>> print vehicle[index]
r
>>> index = 1
>>> print vehicle[index]
a
>>> index = 0
>>> print vehicle[index]
c

Notice that the three print statements are identical.  That suggests
we could write the code in a loop, with 'print vehicle[index]' in the
body of the loop.  Can you have a go at that?

--
John.


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