Re: Use variable outside if statement

If the code is also used at other places, then put in a sub:

use strict;

print foo("abcCj");

sub foo {
    return ($_[0] =~ /TC/g) ? "TC" : "26 ";                
}
[download]

The points here are:

First, the ultimate way to set the right scope for your variables is to modulize your code, fully utilize things like package, class, sub etc.
Always define your variables in the smallest scope that can yet be accessed by all parts that need it

Comment on Re: Use variable outside if statement Download Code

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Re: Re: Use variable outside if statement by davido (Cardinal) on Dec 18, 2003 at 04:22 UTC
That's a very good point. And in situations where a seperate sub may be inconvenient, an enclosing lexical block can be helpful: `use strict; use warnings; my $var = 10; { my $var = 20; print $var, "\n"; } print $var, "\n"; __OUTPUT__ 20 10` [download] ...just a quick demonstration of using {...} blocks to limit scope and protect variables of broader scope. Perl is great at providing mechanisms for lexical scoping: file-based scope, package scope, block scope, subroutine scope, as well as other mechanisms such as `do{...};` and eval. It can be a tricky maze to wander at first, but definately flexible. Perl programmers are lucky in that they can decide just how complex or simple they want their scoping and modularization to be. Dave	[reply] [d/l] [select]
Re: Re: Re: Use variable outside if statement by skyknight (Hermit) on Dec 18, 2003 at 16:33 UTC
That depends on whether you are the guru, able to exploit a rich syntax to create compact and elegant code, or a novice struggling to comprehend what may look like line noise to you. Perl's expressivity as a language can be a wonderful thing, but it comes as a dangerous double edged sword. What is and is not appropriate to write depends on your target audience. Reckless and excessive use of some of Perl's more arcane functionality is what often gets Perl branded as a write only language amongst the unenlightened, and also causes Perl to lean toward unmanageability when code bases grow large.	[reply]