Ruby/Справочник/Object
Класс Object[править]
Object is the parent class of all classes in Ruby. Its methods are therefore available to all objects unless explicitly overridden. Object mixes in the Kernel module, making the built-in kernel functions globally accessible. Although the instance methods of Object are defined by the Kernel module, we have chosen to document them here for clarity. In the descriptions of Object's methods, the parameter symbol refers to a symbol, which is either a quoted string or a Symbol (such as :name).
Same as above, except in Object.
metaprogramming assistant -- metaid.rb
Примеси
Kernel (Array, Float, Integer, Pathname, String, URI, `, abort, at_exit, autoload, autoload?, binding, block_given?, callcc, caller, catch, chomp, chomp!, chop, chop!, eval, exec, exit, exit!, fail, fork, format, gem, getc, gets, global_variables, gsub, gsub!, iterator?, lambda, load, local_variables, loop, method_missing, open, open_uri_original_open, p, pp, pretty_inspect, print, printf, proc, putc, puts, raise, rake_dup, rand, readline, readlines, require, require_gem, scan, scanf, select, set_trace_func, sleep, split, sprintf, srand, sub, sub!, syscall, system, test, throw, to_ptr, trace_var, trap, untrace_var, warn, y),
PP::ObjectMixin (pretty_print, pretty_print_cycle, pretty_print_inspect, pretty_print_instance_variables)
Константы
ARGF, ARGV, DATA, ENV, FALSE, IPsocket, MatchingData, NIL, PLATFORM, RELEASE_DATE, RUBY_PATCHLEVEL, RUBY_PLATFORM, RUBY_RELEASE_DATE, RUBY_VERSION, SOCKSsocket, STDERR, STDIN, STDOUT, TCPserver, TCPsocket, TOPLEVEL_BINDING, TRUE, UDPsocket, UNIXserver, UNIXsocket, VERSION
Методы класса
find_hidden_method, method_added, new
Методы объекта
===, ==, =~, __id__, __send__, class_def, class, clone, dclone, display, dup, enum_for, eql?, equal?, extend, freeze, frozen?, hash, id, inspect, instance_eval, instance_of?, instance_variable_get, instance_variable_set, instance_variables, is_a?, kind_of?, meta_def, meta_eval, metaclass, methods, method, nil?, object_id, private_methods, protected_methods, public_methods, remove_instance_variable, respond_to?, send, singleton_method_added, singleton_method_removed, singleton_method_undefined, singleton_methods, tainted?, taint, to_a, to_enum, to_s, to_yaml_properties, to_yaml_style, to_yaml, type, untaint
[править]
Object::find_hidden_method(name)
(нет описания...)
Object::method_added[править]
Object::method_added(name)
Detect method additions to Object and remove them in the BlankSlate class.
Object::new[править]
Object::new()
Not documented
Object#==[править]
obj == other => true or false obj.equal?(other) => true or false obj.eql?(other) => true or false
Equality---At the Object level, == returns true only if obj and other are the same object. Typically, this method is overridden in descendent classes to provide class-specific meaning. Unlike ==, the equal? method should never be overridden by subclasses: it is used to determine object identity (that is, a.equal?(b) iff a is the same object as b). The eql? method returns true if obj and anObject have the same value. Used by Hash to test members for equality. For objects of class Object, eql? is synonymous with ==. Subclasses normally continue this tradition, but there are exceptions. Numeric types, for example, perform type conversion across ==, but not across eql?, so:
1 == 1.0 #=> true
1.eql? 1.0 #=> false
Object#===[править]
obj === other => true or false
Case Equality---For class Object, effectively the same as calling #==, but typically overridden by descendents to provide meaningful semantics in case statements.
Object#=~[править]
obj =~ other => false
Pattern Match---Overridden by descendents (notably Regexp and String) to provide meaningful pattern-match semantics.
Object#__id__[править]
obj.__id__ => fixnum obj.object_id => fixnum
Document-method: object_id Returns an integer identifier for obj. The same number will be returned on all calls to id for a given object, and no two active objects will share an id. Object#object_id is a different concept from the :name notation, which returns the symbol id of name. Replaces the deprecated Object#id.
Object#__send__[править]
obj.send(symbol [, args...]) => obj obj.__send__(symbol [, args...]) => obj
Invokes the method identified by symbol, passing it any arguments specified. You can use __send__ if the name send clashes with an existing method in obj.
class Klass
def hello(*args)
"Hello " + args.join(' ')
end
end
k = Klass.new
k.send :hello, "gentle", "readers" #=> "Hello gentle readers"
Object#class[править]
obj.class => class
Returns the class of obj, now preferred over Object#type, as an object's type in Ruby is only loosely tied to that object's class. This method must always be called with an explicit receiver, as class is also a reserved word in Ruby.
1.class #=> Fixnum
self.class #=> Object
Object#class_def[править]
class_def(name, &blk)
Defines an instance method within a class
Object#clone[править]
obj.clone -> an_object
Produces a shallow copy of obj---the instance variables of obj are copied, but not the objects they reference. Copies the frozen and tainted state of obj. See also the discussion under Object#dup.
class Klass
attr_accessor :str
end
s1 = Klass.new #=> #<Klass:0x401b3a38>
s1.str = "Hello" #=> "Hello"
s2 = s1.clone #=> #<Klass:0x401b3998 @str="Hello">
s2.str[1,4] = "i" #=> "i"
s1.inspect #=> "#<Klass:0x401b3a38 @str=\"Hi\">"
s2.inspect #=> "#<Klass:0x401b3998 @str=\"Hi\">"
This method may have class-specific behavior. If so, that behavior will be documented under the #initialize_copy method of the class.
Object#dclone[править]
dclone()
(нет описания...)
Object#display[править]
obj.display(port=$>) => nil
Prints obj on the given port (default $>). Equivalent to:
def display(port=$>)
port.write self
end
For example:
1.display
"cat".display
[ 4, 5, 6 ].display
puts
produces:
1cat456
Object#dup[править]
obj.dup -> an_object
Produces a shallow copy of obj---the instance variables of obj are copied, but not the objects they reference. dup copies the tainted state of obj. See also the discussion under Object#clone. In general, clone and dup may have different semantics in descendent classes. While clone is used to duplicate an object, including its internal state, dup typically uses the class of the descendent object to create the new instance. This method may have class-specific behavior. If so, that behavior will be documented under the #initialize_copy method of the class.
Object#enum_for[править]
obj.to_enum(method = :each, *args) obj.enum_for(method = :each, *args)
Returns Enumerable::Enumerator.new(self, method, *args). e.g.:
str = "xyz"
enum = str.enum_for(:each_byte)
a = enum.map {|b| '%02x' % b } #=> ["78", "79", "7a"]
# protects an array from being modified
a = [1, 2, 3]
some_method(a.to_enum)
Object#eql?[править]
obj == other => true or false obj.equal?(other) => true or false obj.eql?(other) => true or false
Equality---At the Object level, == returns true only if obj and other are the same object. Typically, this method is overridden in descendent classes to provide class-specific meaning. Unlike ==, the equal? method should never be overridden by subclasses: it is used to determine object identity (that is, a.equal?(b) iff a is the same object as b). The eql? method returns true if obj and anObject have the same value. Used by Hash to test members for equality. For objects of class Object, eql? is synonymous with ==. Subclasses normally continue this tradition, but there are exceptions. Numeric types, for example, perform type conversion across ==, but not across eql?, so:
1 == 1.0 #=> true
1.eql? 1.0 #=> false
Object#equal?[править]
obj == other => true or false obj.equal?(other) => true or false obj.eql?(other) => true or false
Equality---At the Object level, == returns true only if obj and other are the same object. Typically, this method is overridden in descendent classes to provide class-specific meaning. Unlike ==, the equal? method should never be overridden by subclasses: it is used to determine object identity (that is, a.equal?(b) iff a is the same object as b). The eql? method returns true if obj and anObject have the same value. Used by Hash to test members for equality. For objects of class Object, eql? is synonymous with ==. Subclasses normally continue this tradition, but there are exceptions. Numeric types, for example, perform type conversion across ==, but not across eql?, so:
1 == 1.0 #=> true
1.eql? 1.0 #=> false
Object#extend[править]
obj.extend(module, ...) => obj
Adds to obj the instance methods from each module given as a parameter.
module Mod
def hello
"Hello from Mod.\n"
end
end
class Klass
def hello
"Hello from Klass.\n"
end
end
k = Klass.new
k.hello #=> "Hello from Klass.\n"
k.extend(Mod) #=> #<Klass:0x401b3bc8>
k.hello #=> "Hello from Mod.\n"
Object#freeze[править]
obj.freeze => obj
Prevents further modifications to obj. A TypeError will be raised if modification is attempted. There is no way to unfreeze a frozen object. See also Object#frozen?.
a = [ "a", "b", "c" ]
a.freeze
a << "z"
produces:
prog.rb:3:in `<<': can't modify frozen array (TypeError)
from prog.rb:3
Object#frozen?[править]
obj.frozen? => true or false
Returns the freeze status of obj.
a = [ "a", "b", "c" ]
a.freeze #=> ["a", "b", "c"]
a.frozen? #=> true
Object#hash[править]
obj.hash => fixnum
Generates a Fixnum hash value for this object. This function must have the property that a.eql?(b) implies a.hash == b.hash. The hash value is used by class Hash. Any hash value that exceeds the capacity of a Fixnum will be truncated before being used.
Object#id[править]
obj.id => fixnum
Soon-to-be deprecated version of Object#object_id.
Object#inspect[править]
obj.inspect => string
Returns a string containing a human-readable representation of obj. If not overridden, uses the to_s method to generate the string.
[ 1, 2, 3..4, 'five' ].inspect #=> "[1, 2, 3..4, \"five\"]"
Time.new.inspect #=> "Wed Apr 09 08:54:39 CDT 2003"
Object#instance_eval[править]
obj.instance_eval(string [, filename [, lineno]] ) => obj
obj.instance_eval {| | block } => obj
Evaluates a string containing Ruby source code, or the given block, within the context of the receiver (obj). In order to set the context, the variable self is set to obj while the code is executing, giving the code access to obj's instance variables. In the version of instance_eval that takes a String, the optional second and third parameters supply a filename and starting line number that are used when reporting compilation errors.
class Klass
def initialize
@secret = 99
end
end
k = Klass.new
k.instance_eval { @secret } #=> 99
Object#instance_of?[править]
obj.instance_of?(class) => true or false
Returns true if obj is an instance of the given class. See also Object#kind_of?.
Object#instance_variable_get[править]
instance_variable_get(ivarname)
(нет описания...)
Object#instance_variable_set[править]
instance_variable_set(ivarname, value)
(нет описания...)
Object#instance_variables[править]
obj.instance_variables => array
Returns an array of instance variable names for the receiver. Note that simply defining an accessor does not create the corresponding instance variable.
class Fred
attr_accessor :a1
def initialize
@iv = 3
end
end
Fred.new.instance_variables #=> ["@iv"]
Object#is_a?[править]
obj.is_a?(class) => true or false obj.kind_of?(class) => true or false
Returns true if class is the class of obj, or if class is one of the superclasses of obj or modules included in obj.
module M; end
class A
include M
end
class B < A; end
class C < B; end
b = B.new
b.instance_of? A #=> false
b.instance_of? B #=> true
b.instance_of? C #=> false
b.instance_of? M #=> false
b.kind_of? A #=> true
b.kind_of? B #=> true
b.kind_of? C #=> false
b.kind_of? M #=> true
Object#kind_of?[править]
obj.is_a?(class) => true or false obj.kind_of?(class) => true or false
Returns true if class is the class of obj, or if class is one of the superclasses of obj or modules included in obj.
module M; end
class A
include M
end
class B < A; end
class C < B; end
b = B.new
b.instance_of? A #=> false
b.instance_of? B #=> true
b.instance_of? C #=> false
b.instance_of? M #=> false
b.kind_of? A #=> true
b.kind_of? B #=> true
b.kind_of? C #=> false
b.kind_of? M #=> true
Object#meta_def[править]
meta_def(name, &blk)
Adds methods to a metaclass
Object#meta_eval[править]
meta_eval(&blk;)
(нет описания...)
Object#metaclass[править]
metaclass()
The hidden singleton lurks behind everyone
Object#method[править]
obj.method(sym) => method
Looks up the named method as a receiver in obj, returning a Method object (or raising NameError). The Method object acts as a closure in obj's object instance, so instance variables and the value of self remain available.
class Demo
def initialize(n)
@iv = n
end
def hello()
"Hello, @iv = #{@iv}"
end
end
k = Demo.new(99)
m = k.method(:hello)
m.call #=> "Hello, @iv = 99"
l = Demo.new('Fred')
m = l.method("hello")
m.call #=> "Hello, @iv = Fred"
Object#methods[править]
obj.methods => array
Returns a list of the names of methods publicly accessible in obj. This will include all the methods accessible in obj's ancestors.
class Klass
def kMethod()
end
end
k = Klass.new
k.methods[0..9] #=> ["kMethod", "freeze", "nil?", "is_a?",
"class", "instance_variable_set",
"methods", "extend", "send", "instance_eval"]
k.methods.length #=> 42
Object#nil?[править]
nil?()
call_seq:
nil.nil? => true
<anything_else>.nil? => false
Only the object nil responds true to nil?.
Object#object_id[править]
obj.__id__ => fixnum obj.object_id => fixnum
Returns an integer identifier for obj. The same number will be returned on all calls to id for a given object, and no two active objects will share an id. Object#object_id is a different concept from the :name notation, which returns the symbol id of name. Replaces the deprecated Object#id.
Object#private_methods[править]
obj.private_methods(all=true) => array
Returns the list of private methods accessible to obj. If the all parameter is set to false, only those methods in the receiver will be listed.
Object#protected_methods[править]
obj.protected_methods(all=true) => array
Returns the list of protected methods accessible to obj. If the all parameter is set to false, only those methods in the receiver will be listed.
Object#public_methods[править]
obj.public_methods(all=true) => array
Returns the list of public methods accessible to obj. If the all parameter is set to false, only those methods in the receiver will be listed.
Object#remove_instance_variable[править]
obj.remove_instance_variable(symbol) => obj
Removes the named instance variable from obj, returning that variable's value.
class Dummy
attr_reader :var
def initialize
@var = 99
end
def remove
remove_instance_variable(:@var)
end
end
d = Dummy.new
d.var #=> 99
d.remove #=> 99
d.var #=> nil
Object#respond_to?[править]
obj.respond_to?(symbol, include_private=false) => true or false
Возвращает значение true, если объект отвечает на данный метод. Частные методы включены в поиск только тогда, когда необязательный второй параметр вычисляется как true.
Object#send[править]
obj.send(symbol [, args...]) => obj obj.__send__(symbol [, args...]) => obj
Invokes the method identified by symbol, passing it any arguments specified. You can use __send__ if the name send clashes with an existing method in obj.
class Klass
def hello(*args)
"Hello " + args.join(' ')
end
end
k = Klass.new
k.send :hello, "gentle", "readers" #=> "Hello gentle readers"
Object#singleton_method_added[править]
singleton_method_added(symbol)
Invoked as a callback whenever a singleton method is added to the receiver.
module Chatty
def Chatty.singleton_method_added(id)
puts "Adding #{id.id2name}"
end
def self.one() end
def two() end
def Chatty.three() end
end
produces:
Adding singleton_method_added
Adding one
Adding three
Object#singleton_method_removed[править]
singleton_method_removed(symbol)
Invoked as a callback whenever a singleton method is removed from the receiver.
module Chatty
def Chatty.singleton_method_removed(id)
puts "Removing #{id.id2name}"
end
def self.one() end
def two() end
def Chatty.three() end
class <<self
remove_method :three
remove_method :one
end
end
produces:
Removing three
Removing one
Object#singleton_method_undefined[править]
singleton_method_undefined(symbol)
Invoked as a callback whenever a singleton method is undefined in the receiver.
module Chatty
def Chatty.singleton_method_undefined(id)
puts "Undefining #{id.id2name}"
end
def Chatty.one() end
class << self
undef_method(:one)
end
end
produces:
Undefining one
Object#singleton_methods[править]
obj.singleton_methods(all=true) => array
Returns an array of the names of singleton methods for obj. If the optional all parameter is true, the list will include methods in modules included in obj.
module Other
def three() end
end
class Single
def Single.four() end
end
a = Single.new
def a.one()
end
class << a
include Other
def two()
end
end
Single.singleton_methods #=> ["four"]
a.singleton_methods(false) #=> ["two", "one"]
a.singleton_methods #=> ["two", "one", "three"]
Object#taint[править]
obj.taint -> obj
Marks obj as tainted---if the $SAFE level is set appropriately, many method calls which might alter the running programs environment will refuse to accept tainted strings.
Object#tainted?[править]
obj.tainted? => true or false
Returns true if the object is tainted.
Object#to_a[править]
obj.to_a -> anArray
Returns an array representation of obj. For objects of class Object and others that don't explicitly override the method, the return value is an array containing self. However, this latter behavior will soon be obsolete.
self.to_a #=> -:1: warning: default `to_a' will be obsolete
"hello".to_a #=> ["hello"]
Time.new.to_a #=> [39, 54, 8, 9, 4, 2003, 3, 99, true, "CDT"]
Object#to_enum[править]
obj.to_enum(method = :each, *args) obj.enum_for(method = :each, *args)
Returns Enumerable::Enumerator.new(self, method, *args). e.g.:
str = "xyz"
enum = str.enum_for(:each_byte)
a = enum.map {|b| '%02x' % b } #=> ["78", "79", "7a"]
# protects an array from being modified
a = [1, 2, 3]
some_method(a.to_enum)
Object#to_s[править]
obj.to_s => string
Returns a string representing obj. The default to_s prints the object's class and an encoding of the object id. As a special case, the top-level object that is the initial execution context of Ruby programs returns ``main.
Object#type[править]
obj.type => class
Deprecated synonym for Object#class.
Object#untaint[править]
obj.untaint => obj
Removes the taint from obj.