CODEWITHSUNDEEP
regexperl
Krishnachandra Sharma
Krishnachandra Sharma

Reputation: 1342

Regexp not matching when the string contains a space

I have the following rule to match the pattern in a string.

2 alphanumeric characters, followed by 0 or 1 alphabets, followed by 0 or more spaces, followed by 1 to 4 digits

I tried a regexp, but I am still missing out few cases.

Here is my code:

#!/usr/bin/perl
use strict;
use warnings;
my @quer = ('a1q 1234', '11 asdd', 'as 11aa', 'asdasdasd', 'asdd as', 'asdasd asdassdasd', '11 1231', '11 a 12345', '345 1 1231', '12a 123', 'ab 12', 'ab12');
foreach my $query (@quer) {
    if ($query =~ m/\b[a-zA-Z0-9]{2}[a-zA-Z]{0,1}\s*\b[0-9]{1,4}\b/) {
        print "Matched : $query\n";
    } else {
        print "Doesn't match : $query\n";
    }
}

My code is matching ab 12 but not ab12, but according to the rule, it should match both.

Upvotes: 0

Views: 132

Answers (4)

Madhan
Madhan

Reputation: 1321

if ($query =~ m/[0-9A-z]{2}[A-z]?\s*[0-9]{1,4}$/)

This above code also will work.

Upvotes: 0

user1558455
user1558455

Reputation:

In perl (and some other languages) you have some nice shortcuts for alphanumeric, numbers and stuff like that.

e.g:

\w  Match "word" character (alphanumeric plus "_")
\W  Match non-word character
\s  Match whitespace character
\S  Match non-whitespace character
\d  Match digit character
\D  Match non-digit character

But your problem is the word boundary at the middle (\b)

try this:

if ($query =~ m/\b\w{2}\w?\s*\d{1,4}\b/)

Upvotes: 1

kailash19
kailash19

Reputation: 1821

Try this:

if ($query =~ m/\b[a-zA-Z0-9]{2}[a-zA-Z]{0,1}\s*[0-9]{1,4}\b/) {

It is doing exactly what u asked for!!!

Upvotes: 2

Rohit Jain
Rohit Jain

Reputation: 213223

You are having a word boundary in the middle, which is screwing your regex. Remove it:

if ($query =~ m/\b[a-zA-Z0-9]{2}[a-zA-Z]{0,1}\s*\b[0-9]{1,4}\b/)
                                                 ^
                                             remove this

should be:

if ($query =~ m/\b[a-zA-Z0-9]{2}[a-zA-Z]?\s*[0-9]{1,4}\b/)

Note, [a-zA-Z]{0,1} is same as [a-zA-Z]?

Upvotes: 3

Related Questions