Re: Pragmas use strict and use warnings

On 30 Oct 2007 at 10:22, Paul Lalli wrote:
On Oct 30, 11:15 am, chas.ow...@xxxxxxxxx (Chas. Owens) wrote:
On 10/30/07, Kaushal Shriyan <kaushalshri...@xxxxxxxxx> wrote:
snip> Whats the exact purpose of use strict

snip

The strict pragma has three effects (unless modified by arguments):
1. most variables must be declared (there are some exceptions)

This is a common misperception. use strict 'vars' in fact does not
require anything to be declared. All it requires is that global
variables must be fully qualified. You cannot use the short-name of
globals that belong to the current package.

<snipped>

With strict enabled, the only way to use a short-name of a variable is
to declare a lexical of that name (the right choice) using 'my', or to
disable strict 'vars' on a variable-by-variable case using 'our' (the
wrong choice). This is what leads people to assert "use strict forces
you to declare your variables".

Technicaly you are right, but generally it's better to present use
strict 'vars' as a way to force oneself to declare variables. It may
not be exactly what it does, but it's why it exists.

Plus you forgot two ways to allow using the short names. Apart from
the

our $global;

there is also the older

use vars qw($global);

that does the same, except it is not block, but package scoped;


Another option is to disable use vars for a block:

some( $strict, $code);
{
no strict 'vars';
$global = 784;
}
other( $strict, $code)

Jenda
===== Jenda@xxxxxxxxxxx === http://Jenda.Krynicky.cz =====
When it comes to wine, women and song, wizards are allowed
to get drunk and croon as much as they like.
-- Terry Pratchett in Sourcery

.

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