No, it is because in effect, you execute the following:
undef $old;
$old = {
'child' => {
'parent' => $old, # !!!
'name' => 'bob jr'
},
'name' => 'bob'
};
Obviously, the parent key is assigned the new value of $old, which is, well, undef.
Update: You want to check the Data::Dumper POD for the $Data::Dumper::Purity setting.
#!/usr/bin/perl -w
use strict;
use Data::Dumper;
my $old = {
name => "bob",
child => {
name => "bob jr",
}
};
$old->{child}{parent} = $old;
$Data::Dumper::Purity = 1;
print Data::Dumper->Dump([$old], ['$old']);
__END__
$old = {
'child' => {
'parent' => {},
'name' => 'bob jr'
},
'name' => 'bob'
};
$old->{'child'}{'parent'} = $old;
Update2: it appears
valdez snuck the same point in as I was looking up the POD myself.
Makeshifts last the longest.
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.