Printing the hash values could be simplified thus:

my %hash = ( A => [1,2], 
              B => [4,6]); 
while (my ($k,$v)=each %hash){
   print  qq ($k:  @$v\n)
}

-- Output---
A:  1 2
B:  4 6
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UPDATE:If you want it sorted, here is the code:

my %hash = ( S => [1,2],  B => [4,6],); 
print qq($_: @{$hash{$_}}\n) for sort keys %hash;

--output--(Notice, it IS sorted)--
B: 4 6
S: 1 2
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