# Programming Ruby ### The Pragmatic Programmer's Guide
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class TrueClass |
Parent: | Object
Version: | 1.6

### Index:

& ^ |

The global value `true` is the only instance of class `TrueClass` and represents a logically true value in boolean expressions. The class provides operators allowing `true` to be used in logical expressions.

instance methods
& | `true` & anObject -> anObject
|  | And---Returns `false` if anObject is `nil` or `false`, `true` otherwise.
^ | `true` ^ anObject -> !anObject
|  | Exclusive Or---Returns `true` if anObject is `nil` or `false`, `false` otherwise.
| | `true` | anObject -> `true`
|  | Or---Returns `true`. As anObject is an argument to a method call, it is always evaluated; there is no short-circuit evaluation in this case.
    true |  puts("or")
    true || puts("logical or")
produces:
    or

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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 http://www.opencontent.org/openpub/)).

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