range operators

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks, I am simply trying to use the range (..) operator to push a few elements of one array (up to a defined number) into a new array. I want to do this in one line of code as I attemped below. It's not working!! I can obviously do this quite easy with a for loop etc but want to see how this way works. Thanks a lot!


push @new_array, " $old_array[0] .. $old_array[$count] ";
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Re: range operators by Zaxo (Archbishop) on Jul 02, 2003 at 10:53 UTC
The push operator can take a list in the second argument. What you want is a slice of @old_array: `push @new_array, $count > @old_array ? @old__array : @old_array[0 .. $count-1];` [download] That checks the size of @old_array to see if it has at least $count elements. If less or equal, the whole array is pushed without padding, otherwise the slice of the first $count elements is pushed. After Compline, Zaxo	[reply] [d/l]
Re: range operators by cchampion (Curate) on Jul 02, 2003 at 10:54 UTC
You can use a slice `perl -e '@x=(qw(a b c d e f g)); push @y, @x[2..3]; print "@y\n"' c d` [download] update Damn!. A few moments spent to approve the node made the difference. Zaxo anticipated me by a split second! :)	[reply] [d/l]
Re: range operators by tbone1 (Monsignor) on Jul 02, 2003 at 15:22 UTC
I think the problem is the double quotes, try using parentheses instead, like this. `#! /bin/perl @ar=(3,8); push @new_array, ($ar[0] .. $ar[1]); foreach ( @new_array) { print "$_\n"; }` [download] This gives an array with elements 3,4,5,6,7,8. -- tbone1 Ain't enough 'O's in 'stoopid' to describe that guy. - Dave "the King" Wilson	[reply] [d/l]