perl simple regexp

champ · 07-06-2004, 11:01 AM

Hi....have a very simple reg exp, but I cant get it to work as I want.

Code:

my $digit = 12;

if ($digit =~ /\d/) {
  print ("match\n");
} else {
  print ("not match\n");
}

This prints match, although it should'nt cuz I have 2 digits. But if I change it to \d\d\d, it prints
not match. As it should. The point is that I want to match exactly 1 digit, not 1 or more.

Not sure whats wrong. Any ideas?

keefaz · 07-06-2004, 12:21 PM

try if( $digit =~ /^\d$/ )

meonkeys · 07-06-2004, 12:28 PM

There are many ways to solve this problem, all of which are covered in the Perl Regular Expressions documentation.

Try...

Code:

# match exactly one digit somewhere in string
$digit =~ m/\d{1}/;

# entire string must consist of one digit
$digit =~ m/^\d$/;

# match one digit with non-digits on either side
$digit =~ m/\D\d\D/;

Hope this helps,
-Adam Monsen

champ · 07-07-2004, 03:27 AM

thanks to both of you....I had to add the ^ and $, and it worked.