#!/usr/bin/perl -w
use strict;
 
my $var = "WooHoo\n";
 
print $var if $var =~ /^Woo/;
 
print $var if $var !~ /^Hoo/;
 
if ($var =~ s/W/H/) {print "=~ succeeded\n";}
else {print "=~ failed\n";}
print $var;

if ($var !~ s/H/W/) {print "!~ succeeded\n";}
else {print "!~ failed\n";}
print $var;