Beefy Boxes and Bandwidth Generously Provided by pair Networks
good chemistry is complicated,
and a little bit messy -LW
 
PerlMonks  

Re^2: What causes HASH to print?

by Thelonius (Priest)
on Feb 27, 2007 at 16:32 UTC ( #602326=note: print w/ replies, xml ) Need Help??


in reply to Re: What causes HASH to print?
in thread What causes HASH to print?

If you have "use warnings;" in your code (or run with "perl -w"), you should get the warning:

Reference found where even-sized list expected
If you don't have "use warnings;", then put it in before asking a question. The warnings are there to help you, not annoy you.

UPDATE: And, if the warning is a little obscure, which in this case it is if you haven't seen it before, you can also "use diagnostics;". For example, perl -Mdiagnostics -w pm602312.pl gives:

Reference found where even-sized list expected at pm602312.pl line 2 (W misc) You gave a single reference where Perl was expecting a list with an even number of elements (for assignment to a hash). This usua +lly means that you used the anon hash constructor when you meant to use parens. In any case, a hash requires key/value pairs. %hash = { one => 1, two => 2, }; # WRONG %hash = [ qw/ an anon array / ]; # WRONG %hash = ( one => 1, two => 2, ); # right %hash = qw( one 1 two 2 ); # also fine


Comment on Re^2: What causes HASH to print?
Select or Download Code

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://602326]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others making s'mores by the fire in the courtyard of the Monastery: (8)
As of 2015-07-07 12:38 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









    Results (88 votes), past polls