my $foo = 'First line
Second line
Third line';

##</code><code>##

my $foo = '
    First line<br>
    Second line<br>
    Third line<br>
';

##</code><code>##

my $foo = "
    First line<br>
    $second_line<br>
    <a href=\"foo.html\">Third line</a>
";

##</code><code>##

my $foo = qq{
    First line<br>
    $second_line<br>
    <a href="foo.html">Third line</a>
};

##</code><code>##

2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$