var within reg expression

[kielhd]

Hi NG,

I want to search the keys of the hash %z for the value of $x. If $x
matches $i (line 9), a string should be printed.
$x matches key "Hallo", but there is no output!
Where is my mistake?

Thanks in advance
Henning


01 #!C:/Perl/bin/perl.exe -w
02 $x = "all";
03 %z = (
04 "Ich" => "1",
05 "Du" => "2",
06 "Hallo" => "3"
07 );
08 foreach $i ( keys %z ) {
09 if ( $x =~ /$i/ ) { print "$x is part of $i ...\n"; }
10 }

 

[John Strauss]

On 29 Jul 2003 02:25:34 -0700

Hi NG,

I want to search the keys of the hash %z for the value of $x. If $x
matches $i (line 9), a string should be printed.
$x matches key "Hallo", but there is no output!
Where is my mistake?

Thanks in advance
Henning


01 #!C:/Perl/bin/perl.exe -w
02 $x = "all";
03 %z = (
04 "Ich" => "1",
05 "Du" => "2",
06 "Hallo" => "3"
07 );
08 foreach $i ( keys %z ) {
09 if ( $x =~ /$i/ ) { print "$x is part of $i ...\n"; }
10 }

your mistake is on line 09, where you search $x for pattern $i.
you want to search $i for pattern $x, so change your if condition
to "if ( $i =~ /$i/ )" ...


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[Gunnar Hjalmarsson]

I want to search the keys of the hash %z for the value of $x. If $x
matches $i (line 9), a string should be printed.
$x matches key "Hallo", but there is no output!
Where is my mistake?

09 if ( $x =~ /$i/ ) { print "$x is part of $i ...\n"; }

It should be the other way around:

if ( $i =~ /$x/ )
----------^------^

 

[Eric J. Roode]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

(e-mail address removed) (kielhd) wrote in @posting.google.com:

01 #!C:/Perl/bin/perl.exe -w
02 $x = "all";
03 %z = (
04 "Ich" => "1",
05 "Du" => "2",
06 "Hallo" => "3"
07 );
08 foreach $i ( keys %z ) {
09 if ( $x =~ /$i/ ) { print "$x is part of $i ...\n"; }
10 }

A couple of style comments:

Consider using more meaningful variable names.

Consider using index() instead of a pattern match.

- --
Eric
$_ = reverse sort qw p ekca lre Js reh ts
p, $/.r, map $_.$", qw e p h tona e; print

-----BEGIN PGP SIGNATURE-----
Version: PGPfreeware 7.0.3 for non-commercial use <http://www.pgp.com>

iQA/AwUBPyZBS2PeouIeTNHoEQIKOQCeOMFpHNTqE9nKoxt18eX/QmvKzYkAni37
9UhDOKHu57ULFKXswxoXj7CU
=Mf0y
-----END PGP SIGNATURE-----

 

[news]

you want to search $i for pattern $x, so change your if condition
to "if ( $i =~ /$i/ )" ...

Remember that if $i contains special characters (those recognised by
the RE engine) it will have unexpected consequences.

You may prefer to use this,

if ($x =~ /\Q$i/) ...

Chris

 

[Gunnar Hjalmarsson]

Remember that if $i contains special characters (those recognised
by the RE engine) it will have unexpected consequences.

You may prefer to use this,

if ($x =~ /\Q$i/) ...

This is getting confusing. John made a typo, and Chris illustrated his
point using the original incorrect expression. The pattern is $x:

if ($i =~ /\Q$x/)

 

[John Strauss]

This is getting confusing. John made a typo, and Chris illustrated his
point using the original incorrect expression.

Sorry! You're quite correct

Chris[/QUOTE]


sorry for the confusion. (un)happy fingers.



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