| Description: |
How to write an array formatted by columns.
I'll leave OzzyOsbourne to explain the why's and
wherefore's of this... he asked for it.
The problem was given an array containing values from
A to G, we want to print the values in the appropriate
column... or at least that's what I understood the problem to
be ;-)
Update: Changed @s{split //} = 1;
to @s{split //} = ();. The former works in this
case but is misleading and plain sloppy. It puts
1 in the 'first' value of the hash and
undef in the others. Since all we need
to do is to 'autovivify' the elements of the hash so
that the existance check works, this is OK. However,
don't imagine that it puts '1' in all the hash values.
The updated version is probably clearer.
Update: Rearranged ths code to work on an array
rather than a string. Same principle though.
|
#!perl -w
use strict;
sub print_in_columns {
my %s;
# Push the input array into the hash to indicate which
# columns are present
@s{@_} = ();
# Loop through the permitted values and either print
# the value ( if it exists in the hash %s, or print
# an empty column if it isn't
print exists $s{$_} ? "$_\t" : "\t" for ('A'..'G');
print "\n";
}
print_in_columns split // while <DATA>;
__DATA__
ABC
ADE
AFG
CDB
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