Re^2: Trouble grepping values when hash contains multiple values per key

[dirtdog]

I see the problem now

I'm expecting grep to return true or false, but since this is a list context it will return the actual values. Is there any way to force grep to evaluate these in a scalar context in order to return a "true" or "false" in this case?

[chromatic]

Is there any way to force grep to evaluate these in a scalar context in order to return a "true" or "false" in this case?

Yes, evaluate grep in scalar context. It's that easy!

my $found_any = grep { ... } @whatever;

Boolean context is also a scalar context.

[eyepopslikeamosquito]

my $found_any = grep { ... } @whatever;

Because grep always iterates through the entire list, to stop on the first one found, you might try instead:

use List::MoreUtils qw(any);
my $found_any = any { ... } @whatever;

or:

use List::Util qw(first);
my $found_any = defined first { ... } @whatever;

...though, in practice, it is unlikely to matter, performance-wise, unless @whatever is huge.

As an aside, note that both any and first are built in to Perl 6.

[toolic]

Is there any way to force grep to evaluate these in a scalar context in order to return a "true" or "false" in this case?

Something like:

my @date = grep ...
if (@date) { ... }

[dirtdog]

I just changed the until loop to a while loop and now it's working as expected

Sorry for wasting your time...I was not thinking clearly

while (my @date = grep /$new_ex_date/,@{$countries{$cntry_of_issue}})
        {
                $new_date=get_next_bus_day($new_date);
        }