After perusing through the perldsc, you might come up with something like the following code (untested):

my $johndoe_hours = 0;
foreach my $month ( keys %main } {
   $johndoe_hours += $johndoe_hours + $main{$month}{johndoe};
}

[download]
 


my $johndoe_hours = 0;
foreach my $month ( keys %main } {
   $johndoe_hours += $main{$month}{johndoe};
}

[download]
If you want to get rid of the error message when {johndoe} does not exist in the hash $main{$month} (that is assuming you are using warnings), you might want to do something like the following instead: 
my $johndoe_hours = 0;
foreach my $month ( keys %main } {
   if ( exists $main{$month}{johndoe} ) {
   $johndoe_hours += $johndoe_hours + $main{$month}{johndoe};
   }
}

[download]
 

my $johndoe_hours = 0;
foreach my $month ( keys %main } {
   if ( exists $main{$month}{johndoe} ) {
   $johndoe_hours += $main{$month}{johndoe};
   }
}

[download]
update: Fixed code from doubling johndoe's hours.

-enlil

In reply to Re: HoH Issue(AKA Iterating over hash elements) by Enlil
in thread Iterating over hash elements (was: Sorry to bother you) by Anonymous Monk

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