Re: How to reorder a text file

#!/usr/bin/env perl

use strict;
use warnings;

my $txt = "
Title 1
Line of text A
Line of text B
Title 2
Line of text C
Title 3
Title 4
Line of text D
";

my @reverse;
my @normal = split /(Title \d)/, $txt; 
foreach my $n (0 .. @normal){
  if ($n%2){
    push @reverse, $normal[$n].$normal[$n+1];
  }
}
chomp @reverse;
@reverse = reverse @reverse;

map { print $_."\n" } @reverse;
[download]

Comment on Re: How to reorder a text file Download Code

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Re^2: How to reorder a text file by AnomalousMonk (Archbishop) on Jun 13, 2018 at 12:00 UTC
In the `foreach my $n (0 .. @normal){ if ($n%2){ push @reverse, $normal[$n].$normal[$n+1]; } }` [download] loop, aren't you indexing beyond the end of the `@normal` array? Won't this produce `"Use of uninitialized value..."` warnings if warnings are enabled? Shouldn't the loop range be `for my $n (0 .. $#normal-1) { ... }` instead? (And BTW: Aren't you losing an opportunity to avoid using a `foreach`-loop by not re-writing the loop as a ~~`map`~~ \| void-context map statement? :) Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]

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Re^2: How to reorder a text file
by AnomalousMonk (Archbishop) on Jun 13, 2018 at 12:00 UTC

In the

foreach my $n (0 .. @normal){
  if ($n%2){
    push @reverse, $normal[$n].$normal[$n+1];
  }
}
[download]

@normal

"Use of uninitialized value..."

for my $n (0 .. $#normal-1) { ... }

(And BTW: Aren't you losing an opportunity to avoid using a foreach-loop by not re-writing the loop as a ~~map~~ | void-context map statement? :)

Give a man a fish: <%-{-{-{-<

[reply]
[d/l]
[select]