my %hash;
my $count = 0;
while ( my $line = <DATA> ) {
chomp $line;
next unless $line;
my ( $key, $value ) = split /\s*=\s*/, $line;
$hash{$key} = { 'Order' => $count++,
'Value' => $value
};
}
my @ordered_keys = sort {
$hash{$a}{Order} <=> $hash{$b}{Order}
} keys %hash;
print "$_ = $hash{$_}{Value}\n" for @ordered_keys;
__DATA__
Bart = Simpsons
Elane = Seinfeld
Ross = Friends
Oscar the Grouch = Sesame Street
| [reply]
[d/l] |
You can't get the original order from a hash reference. That information is not preserved anywhere.
However, if you control the code that calls your code, you might get them to us Tie::IxHash objects instead of ordinary hashrefs, and that does preserve the order. | [reply] |
What do I do to get them deref-ed in the same order as they were input..
quite a novel use of terminology there..
To (I think) answer your question a hash by its very
nature has no concept of "order of input"
as you are looking for. However there is another way.
Here is one approach:
:
: Much hand waving.
:
# initialize a couple of things
my %asoc_ary=();
my @key_table=();
:
: fanning the air some more
sub putThingIn {
my ($key,$value)=$_;
push @key_table=$key;
$asoc_ary{$key}=$value;
}
sub getThingsBack {
foreach my $key(@key_table){
print $asco_ary{$key},$/;
}
}
As you add things to the associative array
%asco_ary you are keeping track of what
order they were put there in the array
@key_table. The function push
adds things to an array to the end of the array
which is the equivilant of saying
$key_array[++$#key_array]="thing";.
When you iterate through the key array and use those
values as your keys into your associative array you will
get your values back in the order you stored therm.
| [reply]
[d/l]
[select] |
I think davido's approach is the cleanest/easiest. However, I would avoid the "sort" - since you are creating "@ordered_keys" anyway, why not store them in the right order as they are entered into the hash ?
my %hash;
my @ordered_keys;
while ( my $line = <DATA> ) {
chomp $line;
next unless $line;
my ( $key, $value ) = split /\s*=\s*/, $line;
$hash{$key} = $value;
push @ordered_keys, $key;
}
# No need to sort - @ordered_keys is already in the right sequence...
print "$_ = $hash{$_}\n" for @ordered_keys;
Of course, this begs the question - why use %hash at all - hopefully, you have a reason for that - need quick/random reference to the keys for an unstated reason.
Offense, like beauty, is in the eye of the beholder, and a fantasy.
By guaranteeing freedom of expression, the First Amendment also guarntees offense.
| [reply]
[d/l] |