Re^2: removing duplicates from a string list

do you mean something like this

%ids;

#loop through lines
#add id to the list
$ids{$my_input_id} = 'anything - doesn't matter';

#end loop
@ids = keys %ids
join(',' @ids);
[download]

or this

%ids;

#loop through lines
#add id to the list
$ids{$my_input_id} = 'id';

#end loop
@ids = values %ids
join(',' @ids);
[download]

or does it make no difference?

Comment on Re^2: removing duplicates from a string list Select or Download Code

Replies are listed 'Best First'.
Re^3: removing duplicates from a string list by PeterPeiGuo (Hermit) on Nov 27, 2010 at 21:42 UTC
Always use strict and warnings, so you would have to declare your variable with my. With a hash, the key is unique, but not neccessarily the values. Peter (Guo) Pei	[reply]
Re^3: removing duplicates from a string list by 7stud (Deacon) on Nov 27, 2010 at 22:25 UTC
Because the value you assign to each key is unimportant, you might as well use undef to signify that: `use warnings; use strict; use 5.010; my @arr = qw{ a a b b c c c }; my %hash; @hash{@arr} = undef; use Data::Dumper; say Dumper(\%hash); --output:-- $VAR1 = { 'c' => undef, 'a' => undef, 'b' => undef }; ----------- if (exists $hash{a} ) { say 'yes'; } else { say 'no'; } --output:-- yes ---------- for (keys %hash) { say; } --output:-- c a b` [download] If you are reading lines from a file you can reduce the amount of memory you use at any one time by assigning the lines to the hash one at a time--rather than storing the lines in an array and then doing a gang assignment like above.	[reply] [d/l]

Peter (Guo) Pei