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Hi nandymamith,

  • $a = ''; $b = {};
    You really don't want to use $a and $b which are aliases for the two operands being compared in a sortsub.
  • That been said, $a and $b in above are two different things in perl. While $a is an empty scalar variable, $b is a reference to an anonymous hash, created using curly brackets which is empty in this case

  • However, in this case, you can compare these, printing what you want like so:
    use warnings; use strict; my $empty_str = q{}; my $empty_hash_ref = { q{} => q{}, }; for ( keys %$empty_hash_ref ) { $empty_str eq $_ ? print "PASS" : print "FAIL"; ## print PASS } ## use smartmarch ~~ $empty_str ~~ $empty_hash_ref ? print "PASS" : print "FAIL"; ## print +PASS
  • Note however, that iterating through the hash comparing either the keys or values of the hash with the empty scalar variable, when the hash is empty ( with no variable atall) will print nothing, but using the smart match ~~ Operator will print "FAIL"
  • .
    my $empty_str = q{}; my $empty_hash_ref = {}; ## why? for (keys %$empty_hash_ref){ $empty_str eq $_? print "PASS": print "FAIL"; # print nothing } $empty_str~~$empty_hash_ref?print "PASS": print "FAIL"; # print FAI +L

Hope this helps

If you tell me, I'll forget.
If you show me, I'll remember.
if you involve me, I'll understand.
--- Author unknown to me

In reply to Re: How to compare an empty key with another empty key in associative array by 2teez
in thread How to compare an empty key with another empty key in associative array by nandymamith

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