perl-begin-quiz.markdown

Quiz1

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

print 1;

BEGIN {
    print 2;
}

print 3;

213

Quiz2

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

my $var = 'foo';

BEGIN {
    print $var; 
}

Use of uninitialized value $var in print at /Users/yuki.kokubun/Desktop/perl-quiz/quiz1/quiz1.pl line 8.

Quiz3

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

BEGIN {
    print $var; 
}

my $var = 'foo';

Global symbol "$var" requires explicit package name at /Users/yuki.kokubun/Desktop/perl-quiz/quiz1/quiz1.pl line 6.
BEGIN not safe after errors--compilation aborted at /Users/yuki.kokubun/Desktop/perl-quiz/quiz1/quiz1.pl line 7.

Quiz4

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

my $var;

BEGIN {
    $var = 'foo';
}

print $var; 

foo

Quiz5

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

use Foo;

BEGIN {
    print "main BEGIN\n";
}

print "main\n";

use Bar;

package Foo;
use strict;
use warnings;

print "Foo\n";

BEGIN {
    print "Foo BEGIN\n";
}

1;

package Bar;
use strict;
use warnings;

print "Bar\n";

BEGIN {
    print "Bar BEGIN\n";
}

1;

Foo BEGIN
Foo
main BEGIN
Bar BEGIN
Bar
main