Hi guys,
Here is the code:
my @allwords = ();
my %seen=();
foreach my $curr (@allwords) {
$seen{$curr} = 1;
}
@allwords = keys %seen;
my question is: what will @allwords now contain, or how would the entries in the @allwords array be different after this manipulation?
Thank you!!
I am trying to understand more about this array.
your array @allwords is empty hence foreach loop would never execute
you will still have an empty hash after the foreach loop
thus the last statement won't cause any difference and @allwords would still be empty
if you had some entries in @allwords say,
my @allwords = qw/a b c d a/;
my %seen=();
foreach my $curr (@allwords) {
$seen{$curr} = 1;
}
@allwords = keys %seen;
the foreach loop will assing each element of the array @allwords as a key to %seen hash and each key would have 1 as it's value i.e.,
$seen{$a}=1
$seen{$b}=1
$seen{$c}=1
$seen{$d}=1
$seen{$a}=1 #already exists so would be discarded
however, on the last iteration when $curr is a again, your hash already has a key a with value as 1, so it won't allow a duplicate entry and last element of @allwords would be discarded
@allwords = keys %seen;
keys %seen would return ('a','b','c','d') and assign it to @allwords
hence, in short your code here would remove any duplicate entries in an array
Njoy!! 
You can achieve the same result with map:
my %seen=map { $_ => 1 } @allwords;
@allwords= keys %seen;
THANK YOU!!!
---------- Post updated at 11:39 ---------- Previous update was at 11:39 ----------
THANK YOU!!