#!/usr/bin/perl -w
use strict;

#remove "rows" that don't have a value greater than 75

my $value =75;
my $rLoL = [ [78,43,87], [64,73,72], [99], [65,67,71] ];
@$rLoL = grep { (grep {$_ > $value}@$_)>=1}@$rLoL;
foreach my $ref (@$rLoL)
{
   print "@$ref\n";
}
#prints
#78 43 87
#99

#the inside grep above is used in a scalar context.
#It basically says "do we want to keep this list or not?"
#outside grep passes list ref to output based upon that
#true/false decision.

#grep{} works with anything that can be reduced to a
#yes/no question

#@LoH = grep{keys (%_) > 2}@LoH
#removes hashes from List of Hashes that have fewer
#than 3 keys.