Delete duplicate keys in hash from file

[st12iker]

I managed to write a file to a hash. However the file contains multiple keys and value in the format listed. Note how the values are sorted in descending order.

i.e. of file written to hash

ASDF 5.908
ASDF 5.902
ASDF 5.123
QWER 3.098
QWER 3.023
QWER 3.013
ZXCV 2.345
ZXCV 2.312
ZXCV 2.123
 

I would like to remove the duplicate keys with the lower values I can write a new file with only the highest values for each key

i.e.

ASDF 5.908
QWER 3.098
ZXCV 2.345
 

I tried making a second hash:

%hash2;
for $key (keys %hash2) {
    $value_key = "@{[keys $key}]}";
    if (exists $value_key) {
        delete $key;
    }
}
undef hash2;
print %hash2;
exit;
 

[miller]

my %hash = ();
while (<DATA>) {
    chomp;
    my ($key, $val) = split ' ', $_, 2;
    if (! exists $hash{$key} || $hash{$key} < $val) {
        $hash{$key} = $val;
    }
}
 
# Open Output to new file
foreach my $key (sort {$a cmp $b} keys %hash) {
    print "$key $hash{$key}\n";
}
 
__DATA__
ASDF 5.908
ASDF 5.902
ASDF 5.123
QWER 3.098
QWER 3.023
QWER 3.013
ZXCV 2.345
ZXCV 2.312
ZXCV 2.123
 

- Miller