I've been working with a program that uses Hashes of Hashes and have run into some odd results. My understanding was that a hash key could only have one value, either a string or a reference. So why is it that the following code prints "Red Apple", shouldn'y the second line overwrite the value of $hash{'food'} with a reference? 
 $hash{'food'} = 'Apple';
 $hash{'food'}{'color'} = 'Red';

 print "$hash{'food'}{'color'} $hash{'food'}\n";

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and if that works, and the key is remembering both the string and the reference, then why does this print " Apple"? 
 $hash{'food'}{'color'} = 'Red';
 $hash{'food'} = 'Apple';

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I'm assuming it's because 'Apple' overwrites the reference, but wait, it gets weirder. In the following example, the values of one hash seemingly effect the values of another (completely unrelated) hash. 
 $hash1{'food'}{'color'} = 'Red';
 $hash1{'food'} = 'Apple';

 $hash2{'food'}{'color'} = 'Red';
 $hash2{'food'} = 'Apple';

 print "hash1: $hash1{'food'}{'color'} $hash1{'food'}\n";
 print "hash2: $hash2{'food'}{'color'} $hash2{'food'}\n";

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These both print " Apple" but if you swap the first two lines like so: 
 $hash1{'food'} = 'Apple';
 $hash1{'food'}{'color'} = 'Red';

 $hash2{'food'}{'color'} = 'Red';
 $hash2{'food'} = 'Apple';

 print "hash1: $hash1{'food'}{'color'} $hash1{'food'}\n";
 print "hash2: $hash2{'food'}{'color'} $hash2{'food'}\n";

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Then they both print "Red Apple"! How could %hash1 effect %hash2?

I tested this on both Win2000 Perl 5.6.0 and FreeBSD Perl 5.005.

In reply to HoH Weirdness by Davious

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