#!/usr/bin/perl
use strict;
use warnings;

my @t = (4, -5, 7);
push(@t, -2, 3);
print "@t\n";

unshift(@t,0,-1);
print "@t\n";

$t[3] = 9;
print "@t\n";

@t = map($_*2,@t);
print "@t\n";

@t = grep($_>=0,@t);
print "@t\n";

@t = sort {$b <=> $a} @t;
print "@t\n";