use strict;
use warnings;
use IO::String;

my $ioData;
my $io = IO::String->new($ioData);

# Load the Sting filehandle $io
print $io "This is a test\n";
print $io "If you can see this it works!";

# At this point $ioData contains the text above
# as expected. However, $io is still undefined.

while ( <$io> ) {
    print $_;  
# This print is skipped since
# $io is undefined. I do not think it has anything to do
# with the way I am calling <$io>  since from the 
# debugger, $io is never defined.
}