Is one form of character substitution better than the other, and if so, why?

OfficeLinebacker has asked for the wisdom of the Perl Monks concerning the following question:

Greetings, esteemed monks!

Is one of these superior to the other, and if so, why? given

use strict;
my $contents = param("$a");
[download]

which is better?

my @contents = split( /\n/, $contents );
$contents = join( "<br>", @contents );
[download]

$contents =~ s/\n/<br>/g;
[download]

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I like computer programming because it's like Legos for the mind.

Comment on Is one form of character substitution better than the other, and if so, why? Select or Download Code

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Re: Is one form of character substitution better than the other, and if so, why? by Fletch (Bishop) on Aug 21, 2006 at 15:28 UTC
As always, when in doubt Benchmark. But the substitution's likely going to be the quickest as it won't have the overhead of building the temporary array `@contents` that's (presumably) thrown away after the join is done.	[reply] [d/l]
Re: Is one form of character substitution better than the other, and if so, why? by imp (Priest) on Aug 21, 2006 at 15:37 UTC
For the example you provided the regex approach will run faster and be easier to read. I tend to prefer intuitive code over fast code except when it really matters. To satisfy your curiosity you can play with the Benchmark module, which turnstep wrote a tutorial for in this node. As you benchmark more of your code you may find yourself committing one of the cardinal sins - premature optimization.	[reply]
Re^2: Is one form of character substitution better than the other, and if so, why? by OfficeLinebacker (Chaplain) on Aug 21, 2006 at 17:26 UTC
Thanks, I have to look into premature optimization...it sounds like the kind of thing about which a woman might tell me "It's OK, it happens to everybody." _________________________________________________________________________________ I like computer programming because it's like Legos for the mind.	[reply]
Re^3: Is one form of character substitution better than the other, and if so, why? by CountZero (Bishop) on Aug 21, 2006 at 20:10 UTC
I wouldn't want to be found around women who know what happens to everybody. CountZero "If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law	[reply]
Re: Is one form of character substitution better than the other, and if so, why? by OfficeLinebacker (Chaplain) on Aug 25, 2006 at 14:40 UTC
Greetings, esteemed monks! Well, after looking around, the regexp is my preferred method. I ended up doing this: `my $contents = param("$a"); $contents =~ s/(\n\|\r)/<br>/g; $contents =~ s/(<br>)+/<br>/g;` [download] I suppose you can imagine by now what this is for! Thanks again! Terrence _________________________________________________________________________________ I like computer programming because it's like Legos for the mind.	[reply] [d/l]