autovivification
- autovivification
#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
my $data;
$data->{Foo}{Age} = 23;
print Dumper $data;
if ($data->{Bar}{Age} > 18) {
print "Your are too old\n";
}
print Dumper $data;
delete $data->{Moo}{Age};
print Dumper $data;
Output:
$VAR1 = {
'Foo' => {
'Age' => 23
}
};
$VAR1 = {
'Bar' => {},
'Foo' => {
'Age' => 23
}
};
$VAR1 = {
'Bar' => {},
'Moo' => {},
'Foo' => {
'Age' => 23
}
};