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Programming Ruby The Pragmatic Programmer's Guide |
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class NilClass
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Parent:
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Object
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Version:
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1.6
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Index:
&
^
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nil?
to_a
to_i
to_s
The class of the singleton object nil.
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instance methods
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&
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nil& anObject
-> false
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And---Returns false. As anObject is an
argument to a method call, it is always evaluated; there is no
short-circuit evaluation in this case.
nil && puts("logical and")
nil & puts("and")
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produces:
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^
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nil^ anObject
-> true or false
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Exclusive Or---Returns false if anObject is nil or false, true otherwise.
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nil| anObject
-> true or false
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Or---Returns false if anObject is nil or false, true otherwise.
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nil?
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nil.nil? -> true
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Always returns true.
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to_a
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nil.to_a -> []
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Always returns an empty array.
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to_i
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nil.to_i -> 0
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Always returns zero.
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to_s
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nil.to_s -> ""
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Always returns the empty string.
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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/)).
Distribution of substantively modified versions of this document is
prohibited without the explicit permission of the copyright holder.
Distribution of the work or derivative of the work in any standard
(paper) book form is prohibited unless prior permission is obtained
from the copyright holder.
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