On Monday, 8 בOctober 2007, Ernst, Yehuda wrote:
> I want to enter items to array only if they does not exits there
> (i need 1 item of each type)
> if i have a b c d d d c
> the array will have
> a b c d
That was one of my favorites when I was teaching perl.
Several alternative solutions (with different conditions):
@in = ('a', 'c', 'c', 'd', 'd', 'd', 'c');
1. Assume sorted items (your example), preserve order:
my $prev = 'nosuchvalue';
@out = grep($_ ne $prev && ((($prev) = $_),1), @in);
2. Any order input, preserve order:
undef %saw;
@out = grep(!$saw{$_}++, @in);
3. Any order input, does not preserve order:
undef %a;
@[EMAIL PROTECTED] = ();
@out = keys(%a);
4. Any order input, @in contains (not very large) numbers,
does not preserve order:
@[EMAIL PROTECTED] = @in;
@out = sort @a;
Have fun,
--
Oron Peled Voice/Fax: +972-4-8228492
[EMAIL PROTECTED] http://www.actcom.co.il/~oron
ICQ UIN: 16527398
"Beware of bugs in the above code;
I have only proved it correct, not tried it."
-- Donald E. Knuth
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