use strict;


our $var;


print "var contains an undefined value at first check\n" unless defined $var;


$var = "Chocolate";



print "var contains an undefined value at second check\n" unless defined $var;


$var = undef;

undef($var);



print "var contains an undefined value at third check\n" unless defined $var;


$var = 42;



print "var contains an undefined value at fourth check\n" unless defined $var;



print "Done\n";