Programming Ruby

The Pragmatic Programmer's Guide

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class FalseClass
Parent: Object
Version: 1.6


& ^ |

The global value false is the only instance of class FalseClass and represents a logically false value in boolean expressions. The class provides operators allowing false to participate correctly in logical expressions.

instance methods
& false & anObject -> false

And---Returns false. anObject is always evaluated as it is the argument to a method call---there is no short-circuit evaluation in this case.

^ false ^ anObject -> true or false

Exclusive Or---If anObject is nil or false, returns false; otherwise, returns true.

| false | anObject -> true or false

Or---Returns false if anObject is nil or false; true otherwise.

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Extracted from the book "Programming Ruby - The Pragmatic Programmer's Guide"
Copyright © 2001 by Addison Wesley Longman, Inc. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at

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