@hashA{ 'a'..'d' } = 1..4;;

@hashB{ 'a'..'j' } = 1 .. 10;;

delete $hashB{ $_ } for 'e' .. 'j';;

print scalar %hashA;;
4/8

print scalar %hashB;;
4/16

print join ' ', keys %hashA;;
c a b d

print join ' ', keys %hashB;;
a d c b