[perl-python] problem: reducing comparison (erratum)

[Xah Lee]

Xah Lee wrote:
> In imperative languages such as Perl and Python
> and Java, in general it is not safe to delete
> elements when looping thru a list-like entity.
> (it screws up the iteration) One must make a
> copy first, and work with the copy.

Correction:
When looping thru a list-like entity and delete elements in the vary
list, there's a question whether it will change the iteration. (For
example, if one loops thru 1 to 9, and deleted 8 while at 2, should the
loop still do 8?) For some languages and or list entities, the answer
may be yes or no. However, in imperative languages such as Perl and
Python and Java, often this is not allowed, justified as a protection
to safeguard programers as ignoramuses, but partially because the
internal issues of these languages. (These languages have molded a
generation of programers to question and discourse man-made issues.)

The work around in these languages is always to make a copy of the
list-entity, and work with the copy.

 Xah
 xah at xahlee.org
 http://xahlee.org/PageTwo_dir/more.html