class NilClass

The class of the singleton object nil.

Several of its methods act as operators:

Others act as converters, carrying the concept of nullity to other classes:

While nil doesn’t have an explicitly defined #to_hash method, it can be used in ** unpacking, not adding any keyword arguments.

Another method provides inspection:

inspect

Finally, there is this query method:

nil?

Public Instance Methods

() → true

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 33
def !: () -> true

(untyped obj) → false

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 49
def &: (untyped obj) -> false

Returns false:

false & true       # => false
false & Object.new # => false

Argument object is evaluated:

false & raise # Raises RuntimeError.

===

(nil) → true
(untyped obj) → bool

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 65
def ===: (nil) -> true
         | (untyped obj) -> bool

Returns true or false.

Like Object#==, if object is an instance of Object (and not an instance of one of its many subclasses).

This method is commonly overridden by those subclasses, to provide meaningful semantics in case statements.

(untyped obj) → nil

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 80
def =~: (untyped obj) -> nil

Returns nil.

This method makes it useful to write:

while gets =~ /re/
  # ...
end

(false | nil) → false
(untyped obj) → bool

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 93
def ^: (false | nil) -> false
       | (untyped obj) -> bool

Returns false if object is nil or false, true otherwise:

nil ^ nil        # => false
nil ^ false      # => false
nil ^ Object.new # => true

(nil | false) → false
(untyped obj) → bool

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 208
def |: (nil | false) -> false
       | (untyped obj) -> bool

Returns false if object is nil or false, true otherwise:

nil | nil        # => false
nil | false      # => false
nil | Object.new # => true

inspect

() → "nil"

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 104
def inspect: () -> "nil"

Returns string 'nil':

nil.inspect # => "nil"

nil?

() → true

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 113
def nil?: () -> true

Returns true. For all other objects, method nil? returns false.

rationalize

(?untyped eps) → Rational

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 125
def rationalize: (?untyped eps) -> Rational

Returns zero as a Rational:

nil.rationalize # => (0/1)

Argument eps is ignored.

to_a

() → [ ]

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 135
def to_a: () -> []

Returns an empty Array.

nil.to_a # => []

to_c

() → Complex

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 145
def to_c: () -> Complex

Returns zero as a Complex:

nil.to_c # => (0+0i)

to_d → bigdecimal

() → BigDecimal

Source

# File vendor/bundle/ruby/4.0.0/gems/bigdecimal-4.1.2/lib/bigdecimal/util.rb, line 183
def to_d
  BigDecimal(0)
end

Returns nil represented as a BigDecimal.

require 'bigdecimal'
require 'bigdecimal/util'

nil.to_d   # => 0.0

Returns nil represented as a BigDecimal.

require 'bigdecimal'
require 'bigdecimal/util'

nil.to_d   # => 0.0

Returns nil represented as a BigDecimal.

require 'bigdecimal'
require 'bigdecimal/util'

nil.to_d   # => 0.0

to_f

() → Float

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 155
def to_f: () -> Float

Always returns zero.

nil.to_f   #=> 0.0

to_h

() → { }

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 165
def to_h: () -> {}

Returns an empty Hash.

nil.to_h   #=> {}

to_i

() → 0

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 175
def to_i: () -> 0

Always returns zero.

nil.to_i   #=> 0

to_json

(?JSON::State? state) → String

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/stdlib/json/0/json.rbs, line 1259
def to_json: (?JSON::State? state) -> String

Returns a JSON string for nil: ‘null’.

to_r

() → Rational

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 185
def to_r: () -> Rational

Returns zero as a Rational:

nil.to_r # => (0/1)

to_s

() → ""

Source

# File vendor/bundle/ruby/4.0.0/gems/rbs-4.1.1/core/nil_class.rbs, line 195
def to_s: () -> ""

Returns an empty String:

nil.to_s # => ""