CODEWITHSUNDEEP
perl
Rock
Rock

Reputation: 347

Date validator using subroutine in perl

I have dates say $date1, $date2, $date3. I want to create array of these dates pass to subroutine & want to retrieve status of each date. Regular expression inside subroutine will evaluate date format.
I have create subroutine as DateValidator as,

my @newDateArray = qw /$date1, $date2, $date3/;

foreach (@newDateArray) {
        print "Date used $_ : ";
        DateValidator($_);
}

# Subroutine to evaluate dates 
sub DateValidator {
    my $dateVal=shift;
    if ($dateVal =~ /^20?\d{2}\-0?(:?[1-9]|10|11|12)\-(\d{2})$/) {
        if ($2 <= 31) { 
            print "All DD's are correct\n";
        } else {
            print "Please verify the DD again !\n";
        }
    } else {
        print "Please enter correct date !\n";
    }
}

This does not work as expected. Any help would be appreciated.

Upvotes: 0

Views: 95

Answers (1)

TLP
TLP

Reputation: 67908

The qw() function does not interpolate variables. So this code:

my @newDateArray = qw /$date1, $date2, $date3/;

Needs to be:

my @newDateArray = ($date1, $date2, $date3);

I.e. replace qw() with a simple pair of parentheses.

This is not explicitly mentioned in the documentation, but there is a rather subtle mention:

Evaluates to a list of the words extracted out of STRING, using embedded whitespace as the word delimiters. It can be understood as being roughly equivalent to:

split(" ", q/STRING/);

Where the observant people will notice that a single quoted STRING -- using q() -- will not interpolate variables. This could have been written quite a few hundred times clearer, I agree.

Also, you might notice that the documentation says:

A common mistake is to try to separate the words with comma or to put comments into a multi-line qw-string. For this reason, the use warnings pragma and the -w switch (that is, the $^W variable) produces warnings if the STRING contains the "," or the "#" character.

Which you have not noticed, which makes me suspect that you are not using warnings. This is a very, very bad idea. See Why use strict and warnings? for more information.

Upvotes: 4

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