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in reply to remove both leading and trailing spaces

$val=" Smart Way "; $val=~s/(^\s+|\s+$)//g; print '>'.$val.'<';
  • Comment on Re: remove both leading and trailing spaces

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Re: Re: remove both leading and trailing spaces
by softworkz (Monk) on Sep 26, 2003 at 16:52 UTC
    I find this way to be pretty fast on windoze, can someone benchmark it?
    #!/usr/bin/perl -w
use strict;
my $val="      Smart Way    ";
$val = join (" ",split " ",$val);
print '>'.$val.'<'; # shld give me >Smart Way<

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[reply]
[d/l]
      #!/usr/bin/perl -w
use strict;
use Benchmark;
my $val="      Smart Way    ";

timethese(1000000, {
regex1 => sub {
    my $tmp = $val;
    $tmp =~ s/^\s*(.*?)\s*$/$1/g;
  },
  regex2 => sub {
    my $tmp = $val;
    $val = join (" ",split " ",$val);
  },
  regex3 => sub {
    my $tmp = $val;
    $tmp =~ s/^\s+//;
    $tmp =~ s/\s+$//;
  }
});

      [download]

      __OUTPUT__
      Benchmark: timing 1000000 iterations of regex1, regex2, regex3...
      regex1: 6 wallclock secs ( 5.25 usr + 0.00 sys = 5.25 CPU) @ 190512.48/s (n=1000000)
      regex2: 2 wallclock secs ( 1.83 usr + 0.00 sys = 1.83 CPU) @ 547045.95/s (n=1000000)
      regex3: 2 wallclock secs ( 1.02 usr + 0.00 sys = 1.02 CPU) @ 984251.97/s (n=1000000)
[reply]
[d/l]
        One thing you want to watch with regex2... 
        regex2 => sub {
    my $tmp = $val;
    $val = join (" ",split " ",$val);
  },

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        ... is if the variable has spaces contained in the phrase that you want to keep, this will get rid of them... 
        $var = "     Smart   Way      ";
$val = join (" ",split " ",$val);
print "var:  $var\n";  # $var now "Smart Way", internal spaces gone.

        [download]
        regex1 and regex2 would retain the internal spaces.
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[d/l]
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