icon Top 9 categories map      RocketAware > Perl >

Value of %s can be "0"; test with defined()

Tips: Browse or Search all pages for efficient awareness of Perl functions, operators, and FAQs.



Home

Search Perl pages


Subjects

By activity
Professions, Sciences, Humanities, Business, ...

User Interface
Text-based, GUI, Audio, Video, Keyboards, Mouse, Images,...

Text Strings
Conversions, tests, processing, manipulation,...

Math
Integer, Floating point, Matrix, Statistics, Boolean, ...

Processing
Algorithms, Memory, Process control, Debugging, ...

Stored Data
Data storage, Integrity, Encryption, Compression, ...

Communications
Networks, protocols, Interprocess, Remote, Client Server, ...

Hard World
Timing, Calendar and Clock, Audio, Video, Printer, Controls...

File System
Management, Filtering, File & Directory access, Viewers, ...

    
Value of %s can be "0"; test with defined()
(W) In a conditional expression, you used < HANDLE>, <*> (glob), each(), or readdir() as a boolean value. Each of these constructs can return a value of ``0''; that would make the conditional expression false, which is probably not what you intended. When using these constructs in conditional expressions, test their values with the defined operator.

Source: what's new for perl5.004
Copyright: Larry Wall, et al.
Next: Variable "%s" may be unavailable

Previous: Use of "$$<digit>" to mean "${$}<digit>" is deprecated



(Corrections, notes, and links courtesy of RocketAware.com)


[Overview Topics]

Up to: PERL




Rapid-Links: Search | About | Comments | Submit Path: RocketAware > Perl > perldelta/Value.htm
RocketAware.com is a service of Mib Software
Copyright 2000, Forrest J. Cavalier III. All Rights Reserved.
We welcome submissions and comments