In Files
- complex.c
- object.c
- rational.c
Parent
Files
- grammar.en.rdoc
- test.ja.rdoc
- contributing.rdoc
- contributors.rdoc
- dtrace_probes.rdoc
- extension.ja.rdoc
- extension.rdoc
- globals.rdoc
- keywords.rdoc
- maintainers.rdoc
- marshal.rdoc
- regexp.rdoc
- security.rdoc
- standard_library.rdoc
- syntax.rdoc
- assignment.rdoc
- calling_methods.rdoc
- control_expressions.rdoc
- exceptions.rdoc
- literals.rdoc
- methods.rdoc
- miscellaneous.rdoc
- modules_and_classes.rdoc
- precedence.rdoc
- refinements.rdoc
- README.ja.rdoc
- README.rdoc
Class/Module Index
- ArgumentError
- Array
- BasicObject
- Bignum
- Binding
- Class
- ClosedQueueError
- Comparable
- Complex
- Complex::compatible
- ConditionVariable
- Continuation
- Data
- Dir
- ENV
- EOFError
- Encoding
- Encoding::CompatibilityError
- Encoding::Converter
- Encoding::ConverterNotFoundError
- Encoding::InvalidByteSequenceError
- Encoding::UndefinedConversionError
- EncodingError
- Enumerable
- Enumerator
- Enumerator::Generator
- Enumerator::Lazy
- Enumerator::Yielder
- Errno
- Exception
- FalseClass
- Fiber
- FiberError
- File
- File::Constants
- File::Stat
- FileTest
- Fixnum
- Float
- FloatDomainError
- GC
- GC::Profiler
- Hash
- IO
- IO::EAGAINWaitReadable
- IO::EAGAINWaitWritable
- IO::EINPROGRESSWaitReadable
- IO::EINPROGRESSWaitWritable
- IO::EWOULDBLOCKWaitReadable
- IO::EWOULDBLOCKWaitWritable
- IO::WaitReadable
- IO::WaitWritable
- IOError
- IndexError
- Integer
- Interrupt
- Kernel
- KeyError
- LoadError
- LocalJumpError
- Marshal
- MatchData
- Math
- Math::DomainError
- Method
- Module
- NameError
- NilClass
- NoMemoryError
- NoMethodError
- NotImplementedError
- Numeric
- Object
- ObjectSpace
- ObjectSpace::WeakMap
- Proc
- Process
- Process::GID
- Process::Status
- Process::Sys
- Process::UID
- Process::Waiter
- Queue
- Random
- Random::Formatter
- Range
- RangeError
- Rational
- Rational::compatible
- Regexp
- RegexpError
- RubyVM
- RubyVM::Env
- RubyVM::InstructionSequence
- RuntimeError
- ScriptError
- SecurityError
- Signal
- SignalException
- SizedQueue
- StandardError
- StopIteration
- String
- Struct
- Symbol
- SyntaxError
- SystemCallError
- SystemExit
- SystemStackError
- Thread
- Thread::Backtrace::Location
- Thread::Mutex
- ThreadError
- ThreadGroup
- Time
- TracePoint
- TrueClass
- TypeError
- UnboundMethod
- UncaughtThrowError
- ZeroDivisionError
- fatal
- unknown
NilClass
The class of the singleton object nil
.
Public Instance Methods
false & obj → false
click to toggle source
nil & obj → false
And—Returns false
. obj is always evaluated as it is
the argument to a method call—there is no short-circuit evaluation in this
case.
static VALUE false_and(VALUE obj, VALUE obj2) { return Qfalse; }
obj === other → true or false
click to toggle source
Case Equality – For class Object, effectively the
same as calling #==
, but typically overridden by descendants
to provide meaningful semantics in case
statements.
VALUE rb_equal(VALUE obj1, VALUE obj2) { VALUE result; if (obj1 == obj2) return Qtrue; result = rb_funcall(obj1, id_eq, 1, obj2); if (RTEST(result)) return Qtrue; return Qfalse; }
false ^ obj → true or false
click to toggle source
nil ^ obj → true or false
Exclusive Or—If obj is nil
or false
,
returns false
; otherwise, returns true
.
static VALUE false_xor(VALUE obj, VALUE obj2) { return RTEST(obj2)?Qtrue:Qfalse; }
inspect → "nil"
click to toggle source
Always returns the string “nil”.
static VALUE nil_inspect(VALUE obj) { return rb_usascii_str_new2("nil"); }
nil? → true
click to toggle source
Only the object nil responds true
to
nil?
.
static VALUE rb_true(VALUE obj) { return Qtrue; }
rationalize([eps]) → (0/1)
click to toggle source
Returns zero as a rational. The optional argument eps is always ignored.
static VALUE nilclass_rationalize(int argc, VALUE *argv, VALUE self) { rb_scan_args(argc, argv, "01", NULL); return nilclass_to_r(self); }
to_a → []
click to toggle source
Always returns an empty array.
nil.to_a #=> []
static VALUE nil_to_a(VALUE obj) { return rb_ary_new2(0); }
to_c → (0+0i)
click to toggle source
Returns zero as a complex.
static VALUE nilclass_to_c(VALUE self) { return rb_complex_new1(INT2FIX(0)); }
to_f → 0.0
click to toggle source
Always returns zero.
nil.to_f #=> 0.0
static VALUE nil_to_f(VALUE obj) { return DBL2NUM(0.0); }
to_h → {}
click to toggle source
Always returns an empty hash.
nil.to_h #=> {}
static VALUE nil_to_h(VALUE obj) { return rb_hash_new(); }
to_i → 0
click to toggle source
Always returns zero.
nil.to_i #=> 0
static VALUE nil_to_i(VALUE obj) { return INT2FIX(0); }
to_r → (0/1)
click to toggle source
Returns zero as a rational.
static VALUE nilclass_to_r(VALUE self) { return rb_rational_new1(INT2FIX(0)); }