Changing a loop based on the nature of a reference

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

I feel like there must be a more elegant way to do this. I'm getting data from an online service, and sometimes I get a result with 1 hash, and other times a list of hashes. So what I'm doing now is:

if ($content->{Addresses}{ArrayOfAddressResponse}{AddressResponse} =~ 
+/HASH/) {

foreach my $response ( keys %{$content->{Addresses}{ArrayOfAddressResp
+onse}} ) {
...do stuff...
[download]

and then

if ( $content->{Addresses}{ArrayOfAddressResponse}{AddressResponse} =~
+ /ARRAY/) {

foreach my $response ( @ {$content->{Addresses}{ArrayOfAddressResponse
+}{AddressResponse}} ) {
[download]

The thing is, the "stuff" I'm doing ends up looking identical like:

        print "street: $response->{Street}<br>";
        print "street2: $response>{Street2}<br>";
        print "apt: $response->{UnitNumber}<br>";
[download]

So it just seems very wasteful. I've thought about just making all the print statements a subroutine. But it's the two "if" statements that seem kinda clunky to me. Any input would be greatly appreciated (again)!

Comment on Changing a loop based on the nature of a reference Select or Download Code

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Re: Changing a loop based on the nature of a reference by Your Mother (Archbishop) on Nov 05, 2009 at 05:41 UTC
Stab in the dark: XML::Simple? You might look at the `ForceArray => 1` option. IIRC that would solve your issue by making them all arrays. Tangent- `if ( $content->{Addresses}{ArrayOfAddressResponse}{AddressResponse} =~ /ARRAY/ )` -is probably better as something like- `my $item = $content->{Addresses}{ArrayOfAddressResponse}{AddressRespon +se}; if ( ref($item) eq 'ARRAY' ) ...` [download] Update: there's also this sort of thing- `my $address_ref = $content->{Addresses}{ArrayOfAddressResponse}{Addres +sResponse}; my $addresses = ref($address_ref) eq 'HASH' ? [ $address_ref ] : $address_ref;` [download] -which will always give you back an array ref of hashes. Note that it doesn't account for unexpected values, e.g., undef, a scalar, a different type of ref, etc.	[reply] [d/l] [select]
Re: Changing a loop based on the nature of a reference by colwellj (Monk) on Nov 05, 2009 at 05:49 UTC
Why not pretend that your returned hash is actually a list of 1 hash. i.e `my @myarray; push @myarray, @{$content->{Addresses}{ArrayOfAddressResponse}{Address +Response}}; foreach my $response ( @myarray ) { do stuff... }` [download] I think this might work. You may even be able to directly reference without the push. John	[reply] [d/l]
Re^2: Changing a loop based on the nature of a reference by rastoboy (Monk) on Nov 05, 2009 at 07:47 UTC
Your Mother: On the money, yes, XML::Simple. And I think that is likely the best way to fix it this time--thanks! I also like your terniary method. Mostly because I look for any opportunity to use the terniary operator :-) Nah but actually that seems pretty nice. :-) Thanks to all!	[reply]