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Perl Language Reference Manual
by Larry Wall and others
Paperback (6"x9"), 724 pages
ISBN 9781906966027
RRP £29.95 ($39.95)

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Can't call method "%s" on an undefined value

(F) You used the syntax of a method call, but the slot filled by the object reference or package name contains an undefined value. Something like this will reproduce the error:

$BADREF = undef;
process $BADREF 1,2,3;
$BADREF->process(1,2,3);
ISBN 9781906966027Perl Language Reference ManualSee the print edition