Re: How can i compare strings using non-case-sensitive comparisions?

Use case-insensitive match

if ($x =~ /^$y$/i) {
    #whatever
}
[download]

In my benchmark the two methods take substantially the same time.
Rudif

#! perl -w

use strict;
use Benchmark;

my $x='The Monastery Gates';
my $y='http://www.perlmonks.org/';

timethese(1000000,{eq=>sub{ if (lc $x eq lc $y) {} }, re=>sub{ if ($x 
+=~ /^$y$/i) {} }})

__END__

Benchmark: timing 1000000 iterations of a, b...
         eq:  1 wallclock secs ( 1.12 usr +  0.00 sys =  1.12 CPU) @ 8
+91265.60/s (n=1000000)
         re:  2 wallclock secs ( 1.06 usr +  0.00 sys =  1.06 CPU) @ 9
+79431.93/s (n=1000000)
[download]

Comment on Re: How can i compare strings using non-case-sensitive comparisions? Select or Download Code

Replies are listed 'Best First'.
Re: Answer: How can i compare strings using non-case-sensitive comparisions? by chipmunk (Parson) on Jan 16, 2001 at 04:18 UTC
How about a Benchmark where the strings do match? `#!perl -w use strict; use Benchmark qw/ cmpthese /; my $x = 'The Monastery Gates'; my $y = 'ThE MoNaStErY GaTeS'; cmpthese(-(shift), { eq => sub{ if (lc $x eq lc $y) {} }, re => sub{ if ($x =~ /^$y$/i) {} }, } ) __END__ Benchmark: running eq, re, each for at least 3 CPU seconds... eq: 6 wallclock secs ( 3.04 usr + 0.01 sys = 3.05 CPU) @ 24 +2974.43/s (n=741072) re: 8 wallclock secs ( 3.00 usr + 0.00 sys = 3.00 CPU) @ 86 +303.00/s (n=258909) Rate re eq re 86303/s -- -64% eq 242974/s 182% --` [download] That's not all, though. When the strings don't match and $y is shorter, eq comes out about 220% ahead. When $y is longer and the regex optimizer can tell right off that $x is too short for /^$y$/ to match, eq still has a 40% advantage.	[reply] [d/l]
Re: Answer: How can i compare strings using non-case-sensitive comparisions? by I0 (Priest) on Jan 16, 2001 at 21:52 UTC
`my $x='http://wwwperlmonksorg/'; my $y='http://www.perlmonks.org/'; sub{ if ($x =~ /^$y$/i) {} }` [download] matches slowly and incorrectly	[reply] [d/l]


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