CODEWITHSUNDEEP
perl
Ecognium
Ecognium

Reputation: 2076

How to check if an object exists

I am trying to extract the domain part of a URL and I want to cover the case where the input is invalid. 

 use strict;
 use warnings;
 use URI;
 use Data::Dumper;

 my $url = URI->new( "garbled" );
 # my $url = URI->new( "http://www.google.com/" ); # this works
 # print Dumper $url;
 print $url->host if defined($url->host) ;

Gives Can't locate object method "host" via package "URI::_generic" at

How can check if the URL was parsed correctly?

Upvotes: 2

Views: 272

Answers (1)

mob
mob

Reputation: 118605

For the general case you can use UNIVERSAL::can

if (ref($url) && $url->can("host")) { ... }

or exception handling

eval { print $url->host };
if ($@) { warn "\$url wasn't what I thought it was" }

but in most cases you would want to drill down into the error and find the mismatch between your expectations and the program's behavior.

Upvotes: 3

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