pattern matching

r_mehmed has asked for the wisdom of the Perl Monks concerning the following question:

Hello Monks, I'm a real newbie,so this might be an easy task to most of you to tackle. I'm trying to pattern macth the date,any date, in a text and then add 'st','nd','rd','th' after each day of the month. All attempts to use an array failed, therefore i opted for the 'easier' solution, but i have hit rock yet again. The code simply doesn't seem to iterate through the if..elsif statements, and always adds the 'st'. This is the code i am using:

#!perl<br> 
use CGI;<br>
$query = new CGI;<br>
$source = $query->param('input');<br>
print $query->header;<br>

$source =~ m/(\d{1,2})(\/|\-)(\d{1,2})(\/|\-)(\d{2,4})/g;<br>

my $day = $1;<br>
if($day == 1,21,31){<br>
    $day = "$day\st"<br>
}elsif($day == 2|22){<br>
    $day = "$day\nd"<br>
}elsif($day == 3|23){<br>
    $day = "$day\rd"<br>
}elsif($day == 4-20|24-30){<br>
    $day = "$day\th"<br>
}<br>
print "$day";<br>
[download]

Pls help!!!

Added <code> tags - dvergin 2002-11-31

Comment on pattern matching Download Code

Replies are listed 'Best First'.
Re: pattern matching by tachyon (Chancellor) on Nov 01, 2002 at 01:03 UTC
Very close but you can't do it quite that way. Here is your code in working form: `$source =~ m!(\d{1,2})[-/](\d{1,2})[-/](\d{2,4})!g; my $day = $1; if( $day == 1 or $day == 21 or $day == 31 ){ $day .= 'st'; }elsif( $day == 2 or $day == 22 ){ $day .= 'nd'; }elsif( $day == 3 or $day == 23 ){ $day .= 'rd'; }else { $day .= 'th'; }` [download] I have shown you the use or character classes and different regex delimiters (you can use ! or anything else for that matter, not just /) as well as the .= operator. A little indenting makes it easier to read. The last case is just an else as we want to catch everything that is not a st/nd/rd with th This also works and demonstrates an alternative to the if elseif else structure for simple stuff `$day .= ( $day == 1 or $day == 21 or $day == 31 ) ? 'st' : ( $day == 2 or $day == 22 ) ? 'nd' : ( $day == 3 or $day == 23 ) ? 'rd' : 'th';` [download] cheers tachyon s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print	[reply] [d/l] [select]
Re: pattern matching by kelan (Deacon) on Nov 02, 2002 at 05:20 UTC
Here's a Perl6 regex to do the matching. `### <Perl6> $source =~ / $day:=(\d<1,2>) <[-/]> (\d<1,2>) <[-/]> (\d<2,4>) /; ### </Perl6>` [download] After the match, `$day` will be bound to what was captured in `$1`, and you can proceed to appending suffixes as mentioned above by tachyon. I much like the method using the ternary operator. On a side note, why are you using the /g modifier in your match? I can't see any purpose that it serves. kelan Perl6 Grammar Student	[reply] [d/l]