I'm sure there's an answer to this question, but I don't know the right term to use to find it. If I search for hash I get a lot of info about hashes but nothing about this: 
#!/usr/local/bin/perl

%c={A=>'0',B=>'0',C=>'0',D=>'0'};
foreach $key (keys %c) { print "$key => $c{$key}\n"; }

[download]
Output is:
HASH(0x1b9550c) =>

Why? Shouldn't this code print all the values of %c?

=================================

You know what? I answered my own question, so now it's an FYI for idjits like me.

The problem here is (1) I'm stupid and (2) I need to learn the difference between {} which creates an anonymous hash and () which specifies a list of values.

So %c={A=>'0',B=>'0',C=>'0',D=>'0'}; gives HASH() because you've told perl to add a self-contained hash as the key for the first value of %c.

Extra credit: What is the value of that first key? Nothing, because all you've specified is the key.

BUT %c=(A=>'0',B=>'0',C=>'0',D=>'0'); gives A=>0, B=>0, C=>0, D=>0 because you've told perl to add four key/value pairs to %c.

I hope this helps someone, because this forum has been extremely helpful to me. If some newbie can avoid getting a divorce because he doesn't have to spend 4 hours at work figuring this out like I did, I will be a happy person.

In reply to Trying to print the contents of a hash, but getting a reference. by l_millr

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