You could use HASHES OF HASHES

my %town;
$town{G}{6} = 7; # 7 houses on street 6 in town G
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Update: Here is degit's original question:

I have been working in a perl code and been having a problem, especially in using the "hash". I am a newbie in perl, i would appreciate some help. This is a simple scenario... We have Town A to Z and they have streets 1 to 9 and each street has different number of houses... I would like to find out how to represent the data- eg. G6 = number of houses in town G street 6... and such information sassociated with the keys? PLease help?