CODEWITHSUNDEEP
perlcompareequals
shinjuo
shinjuo

Reputation: 21032

Compare two strings regardless of case size in perl

is there anyway to compare two strings regardless of case size? For Example 

"steve" eq "STevE"   <----- these would match
"SHOE" eq "shoe"

You get the picture

Upvotes: 17

Views: 41116

Answers (3)

DVK
DVK

Reputation: 129481

yes - use uc() (upper-case function; see http://perldoc.perl.org/functions/uc.html )

UPDATE: As per the excellent comment by Brian D Foy below, fc() is better than uc() since it implements official case folding.

$ perl -e 'print uc("steve") eq uc("STevE"); print "\n";'
1
$ perl -e 'print uc("SHOE") eq uc("shoe"); print "\n";'          
1
$ perl5.8 -e 'print uc("SHOE") eq uc("shoe1"); print "\n";'

$

You can obviously use lc() as well.

If you want the actual "eq" operator to be case insensitive, it might be possible using overloads but I don't think that's what you are asking for - please clarify your question if that's the case. Nor is it a great idea if you do want that, IMHO - too fragile and leads to major possible hard to trace and debug bugs.

Also, it's an overkill in your specific case where you just want equality, but Perl regular expressions also have case-independent modifyer "i"

Upvotes: 20

Zaid
Zaid

Reputation: 37146

A couple of ways to do this:

  • Use the lc or uc operator, which converts both strings to lower or upper case respectively:

    lc "steve" eq lc "STevE";

  • A simple regex will do just as well:

    'steve' =~ /^STevE$/i;

Upvotes: 15

Alexander Balyuk
Alexander Balyuk

Reputation: 71

According to perldoc (http://perldoc.perl.org/functions/fc.html), it's better to use

fc("steve") eq fc("STevE")

Don't forget to add this line before first use of fc:

use feature 'fc';

Upvotes: 7

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