if && condition not working

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

Wise Monks, I have a simple if && condition which is not working for me. I am perplexed. Please help. The code is below: Regards, Rakhee

sub validate_date {

        my $start_date = $_[0];
        my $end_date = $_[1];
        my $today_date = $_[2];
        my @start_date_array = split(/\//, $start_date);
        my @end_date_array = split(/\//, $end_date);
        my @today_date_array = split(/\//, $today_date);
        my $error_msg = "";
        if (!$start_date || !$end_date){
        $error_msg = "Blank Field in Date field. Please Use Browser Ba
+ck button and Enter Date Field"};
        if ( (@start_date_array[0] > @today_date_array[0]) && (@start_
+date_array[1] > @today_date_array[1]) && (@start_date_array[2] > @tod
+ay_date_array[2])) {
        $error_msg = "Start Date can not be a Future Date. Please Use 
+Browser Back button and Enter Start Date"};
        if ( (@end_date_array[0] > @today_date_array[0]) && (@end_date
+_array[1] > @today_date_array[1]) && (@end_date_array[2] > @today_dat
+e_array[2])) {
        $error_msg = "End Date can not be a Future Date. Please Use Br
+owser Back button and Enter End Date"};
        return $error_msg;

}
[download]

Comment on if && condition not working Download Code

Replies are listed 'Best First'.
Re: if && condition not working by ikegami (Patriarch) on Mar 24, 2010 at 19:13 UTC
Start by not hiding/ignoring warnings Scalar value @start_date_array[0] better written as $start_date_array[ +0] at a.pl line 12. Scalar value @today_date_array[0] better written as $today_date_array[ +0] at a.pl line 12. Scalar value @start_date_array[1] better written as $start_date_array[ +1] at a.pl line 12. Scalar value @today_date_array[1] better written as $today_date_array[ +1] at a.pl line 12. Scalar value @start_date_array[2] better written as $start_date_array[ +2] at a.pl line 12. Scalar value @today_date_array[2] better written as $today_date_array[ +2] at a.pl line 12. Scalar value @end_date_array[0] better written as $end_date_array[0] a +t a.pl line 14. Scalar value @today_date_array[0] better written as $today_date_array[ +0] at a.pl line 14. Scalar value @end_date_array[1] better written as $end_date_array[1] a +t a.pl line 14. Scalar value @today_date_array[1] better written as $today_date_array[ +1] at a.pl line 14. Scalar value @end_date_array[2] better written as $end_date_array[2] a +t a.pl line 14. Scalar value @today_date_array[2] better written as $today_date_array[ +2] at a.pl line 14. [download] Mind you, that warning doesn't indicate a real problem here (it points out a bad style/habit that can have an effect in uncommon circumstances), but who knows what other warnings are being issued. Add `use warnings;` if it's not already there.	[reply] [d/l] [select]
Re: if && condition not working by ikegami (Patriarch) on Mar 24, 2010 at 19:20 UTC
Sounds like the dates are in the yyyy/mm/dd format, so why not just compare the strings with `lt`/`gt`? `sub validate_date { my ($start_date, $end_date, $today) = @_; return "Invalid format for start date (expecting yyyy/mm/dd)" if $start_date !~ m{^\d{4}/\d{2}/\d{2}\z}; return "Invalid format for end date (expecting yyyy/mm/dd)" if $end_date !~ m{^\d{4}/\d{2}/\d{2}\z}; return "End date must be no later than today" if $end_date gt $today; return "Start date must be no later than end date" if $start_date gt $end_date; return ""; }` [download]	[reply] [d/l] [select]
Re^2: if && condition not working by rakheek (Sexton) on Mar 24, 2010 at 21:36 UTC
Thanks, Ikegami. I will use the string comparison. Do you know if I need to get rid of the / in the date? I can give it a try. Regards, Rakhee	[reply]
Re^3: if && condition not working by ikegami (Patriarch) on Mar 24, 2010 at 23:45 UTC
"/" equals "/", so no need to remove them. `gt` performs a string comparison, not a numerical one.	[reply] [d/l]
Re: if && condition not working by toolic (Bishop) on Mar 24, 2010 at 19:14 UTC
Use perltidy to neaten up your code. Maybe you will be less confused. use strict and warnings. I get warning messages when I compile your code: `perl -wc -Mdiagnostics 830638.pl` [download] You should eliminate the warnings before proceeding. Also, consider using one of the many CPAN Date modules. Date::Calc has a "How do I compare two dates?" recipe.	[reply] [d/l]
Re: if && condition not working by Anonymous Monk on Mar 24, 2010 at 18:58 UTC
Can you show us your data?	[reply]
Re^2: if && condition not working by Anonymous Monk on Mar 24, 2010 at 19:06 UTC
A date in the future can have the same month and year as today. Tomorrow is a good example (assuming today is not the last day of the month or year).	[reply]
Re^3: if && condition not working by ikegami (Patriarch) on Mar 24, 2010 at 19:14 UTC
assuming today is not the last day of the month or year He doesn't handle that either, mind you.	[reply]
Re^2: if && condition not working by rakheek (Sexton) on Mar 24, 2010 at 19:06 UTC
Thanks for replying Anonymous Monk. Yes, my data is right. I printed it out. Also, if I use if condition without the &&, it works. I am totally confused. Here is what worked: sub validate_date { my $start_date = $_[0]; my $end_date = $_[1]; my $today_date = $_[2]; my @start_date_array = split(/\//, $start_date); my @end_date_array = split(/\//, $end_date); my @today_date_array = split(/\//, $today_date); my $error_msg = ""; if (!$start_date \|\| !$end_date){ $error_msg = "Blank Field in Date field. Please Use Browser Ba +ck button and Enter Date Field"}; # if ( (@start_date_array[0] > @today_date_array[0]) && (@start_ +date_array[1] > @today_date_array[1]) && (@start_date_array[2] > @tod +ay_date_array[2])) { if (@start_date_array[0] > @today_date_array[0]) { $error_msg = "Start Date can not be a Future Date. Please Use +Browser Back button and Enter Start Date"}; if ( (@end_date_array[0] > @today_date_array[0]) && (@end_date +_array[1] > @today_date_array[1]) && (@end_date_array[2] > @today_dat +e_array[2])) { $error_msg = "End Date can not be a Future Date. Please Use Br +owser Back button and Enter End Date"}; return $error_msg; } [download]	[reply] [d/l]
Re^3: if && condition not working by kennethk (Abbot) on Mar 24, 2010 at 19:19 UTC
The request was not if your data is properly formatted. The request was to show us examples, so we know what to feed into the subroutine to test it. How are your dates formatted? Is it month/day/year, day/month/year, year/month/day? Is January represented by "1" or "01"? This information is very significant for showing you how your code is incorrect.	[reply]


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