Re: Use of uninitialized value in concatenation

The minimum the regex can match is a $ because the second capture is optional. If there are no \w characters following a $ character then the second capture will be undef and you get the warning. There are two ways you can fix it depending on the desired result. Using

(\$(\w+))
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prints '$Word $' for the sample line, and

(\$(\w*))
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prints '$Word dollar'.

True laziness is hard work

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Re^2: Use of uninitialized value in concatenation by gem555 (Acolyte) on Jun 11, 2009 at 05:42 UTC
For the example like this `#!/usr/bin/perl -w use strict; my %words = map { $_ => 1 } qw($Word $name); my $line = '$Word $ $1'; $line =~ s/(\$(\w+)?)/exists $words{$1} ? $1 : "dollar$2"/eg; print "$line\n\n";` [download] It gives a warning message	[reply] [d/l]
Re^3: Use of uninitialized value in concatenation by AnomalousMonk (Archbishop) on Jun 11, 2009 at 06:00 UTC
Yes, it does. Why don't you try GrandFather's or targetsmart's or my suggestions?	[reply]
Re^4: Use of uninitialized value in concatenation by gem555 (Acolyte) on Jun 11, 2009 at 06:18 UTC
The "$testing" is replaced with "dollar" with the below code `#!/usr/bin/perl -w use strict; use warnings; my %words = map { $_ => 1 } qw($Word $name $test); my $line = '$Word $ $ $ $test $testing'; $line =~ s/(\$\w*)/exists $words{$1} ? $1 : " dollar "/eg; print "$line\n\n"` [download] The output which i need is if the values are not present in array, then $Word dollar dollar dollar $test dollartesting	[reply] [d/l]
Re^5: Use of uninitialized value in concatenation by AnomalousMonk (Archbishop) on Jun 11, 2009 at 06:24 UTC