my %h; @h{ map{ int rand 100 } 1..4 } = 'A'..'D';
print 'Before:', %h, $/;
my $keys = keys %h;
@h{ 1 .. $keys } = delete @h{ keys %h };
print 'After: ', %h, $/;
__END__
Before:6D59B60A75C
After: 4C1D3A2B