Beefy Boxes and Bandwidth Generously Provided by pair Networks
No such thing as a small change
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

It took me a minute or three to figure out what the problem was. Correct me if I'm wrong: When you run the code, you get a "Can't use an undefined value as an ARRAY reference at scriptname.pl line 21" error and you aren't sure why.

I can answer that part -- but what I can't answer is exactly what you're trying to do. The for loop is iterating from 0 to the maximum index in $ref_a. That reference is larger than what you'll find in $ref_b. Some simple print statement debugging will help show what I mean:

print "ref_a: ", $#$ref_a, "\nref_b: ", $#$ref_b, "\n"; for my $i (0..$#$ref_a) { print "Reading element $i\n"; push @{$ref_a->[$i]}, @{$ref_b->[$i]}; }

With some output:

ref_a: 5 ref_b: 2 Reading element 0 Reading element 1 Reading element 2 Reading element 3 Can't use an undefined value as an ARRAY reference at scriptname.pl li +ne 23

To correct this problem, you can just choose the minimum of the two ref_a/b indices. But since I don't know what your goal is, I don't know if this will correct your issue.


In reply to Re: Undefined Array Reference by Nkuvu
in thread Undefined Array Reference by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • 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.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others studying the Monastery: (6)
As of 2023-01-31 23:21 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found

    Notices?