http://www.perlmonks.org?node_id=1175766

Testing a hash to see if it has values for all required keys. Extraneous keys are okay.

use strict; use warnings; use Test::More tests => 3; my (%required,%over,%under,%partial); $required{$_} = 1 for qw/header detail trailer/; $over{$_} = $_ for qw/title header subject detail trailer postscript/; $under{$_} = $_ for qw/header trailer/; $partial{$_} = $_ for qw/header trailer/; $partial{detail} = undef; ok(test_it(%over),'checking %over for required keys'); ok(test_it(%under),'checking %under for required keys'); ok(test_it(%partial),'checking %partial for required keys'); sub test_it { my %h = @_; # return (grep {$required{$_} && $h{$_}} keys %h) == (keys %required) +; return (grep {$required{$_} && defined $h{$_}} keys %h) == (keys %r +equired); }

Update: use of defined suggested by choroba. I would have run into this because 0 is a value I would encounter.

But God demonstrates His own love toward us, in that while we were yet sinners, Christ died for us. Romans 5:8 (NASB)