Class: Object
Overview
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).
Instance Method Summary collapse
- 
  
    
      #==  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Equality—At the
Objectlevel,==returnstrueonly if obj and other are the same object. - 
  
    
      #===(other)  ⇒ Boolean 
    
    
  
  
  
  
  
  
  
  
  
    
Case Equality—For class
Object, effectively the same as calling#==, but typically overridden by descendents to provide meaningful semantics incasestatements. - 
  
    
      #=~(other)  ⇒ false 
    
    
  
  
  
  
  
  
  
  
  
    
Pattern Match—Overridden by descendents (notably
RegexpandString) to provide meaningful pattern-match semantics. - 
  
    
      #hash  ⇒ Fixnum 
    
    
  
  
  
  
  
  
  
  
  
    
Generates a
Fixnumhash value for this object. - 
  
    
      #__send__  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Invokes the method identified by symbol, passing it any arguments specified.
 - 
  
    
      #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. - 
  
    
      #clone  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Produces a shallow copy of obj—the instance variables of obj are copied, but not the objects they reference.
 - 
  
    
      #dup  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Produces a shallow copy of obj—the instance variables of obj are copied, but not the objects they reference.
 - 
  
    
      #eql?  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Equality—At the
Objectlevel,==returnstrueonly if obj and other are the same object. - 
  
    
      #equal?  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Equality—At the
Objectlevel,==returnstrueonly if obj and other are the same object. - 
  
    
      #extend  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Adds to obj the instance methods from each module given as a parameter.
 - 
  
    
      #freeze  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Prevents further modifications to obj.
 - 
  
    
      #frozen?  ⇒ Boolean 
    
    
  
  
  
  
  
  
  
  
  
    
Returns the freeze status of obj.
 - 
  
    
      #hash  ⇒ Fixnum 
    
    
  
  
  
  
  
  
  
  
  
    
Generates a
Fixnumhash value for this object. - 
  
    
      #id  ⇒ Fixnum 
    
    
  
  
  
  
  
  
  
  
  
    
Soon-to-be deprecated version of
Object#object_id. - 
  
    
      #initialize  ⇒ Object 
    
    
  
  
  
    constructor
  
  
  private
  
  
  
  
    
Not documented.
 - 
  
    
      #initialize_copy  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
:nodoc:.
 - 
  
    
      #inspect  ⇒ String 
    
    
  
  
  
  
  
  
  
  
  
    
Returns a string containing a human-readable representation of obj.
 - 
  
    
      #instance_eval  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Evaluates a string containing Ruby source code, or the given block, within the context of the receiver (obj).
 - 
  
    
      #instance_of?  ⇒ Boolean 
    
    
  
  
  
  
  
  
  
  
  
    
Returns
trueif obj is an instance of the given class. - 
  
    
      #instance_variable_defined?(symbol)  ⇒ Boolean 
    
    
  
  
  
  
  
  
  
  
  
    
Returns
trueif the given instance variable is defined in obj. - 
  
    
      #instance_variable_get(symbol)  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Returns the value of the given instance variable, or nil if the instance variable is not set.
 - 
  
    
      #instance_variable_set(symbol, obj)  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Sets the instance variable names by symbol to object, thereby frustrating the efforts of the class’s author to attempt to provide proper encapsulation.
 - #instance_variables ⇒ Object
 - 
  
    
      #is_a?  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Returns
trueif class is the class of obj, or if class is one of the superclasses of obj or modules included in obj. - 
  
    
      #kind_of?  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Returns
trueif class is the class of obj, or if class is one of the superclasses of obj or modules included in obj. - 
  
    
      #method(sym)  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Looks up the named method as a receiver in obj, returning a
Methodobject (or raisingNameError). - 
  
    
      #methods  ⇒ Array 
    
    
  
  
  
  
  
  
  
  
  
    
Returns a list of the names of methods publicly accessible in obj.
 - 
  
    
      #nil?  ⇒ Boolean 
    
    
  
  
  
  
  
  
  
  
  
    
call_seq: nil.nil? => true <anything_else>.nil? => false.
 - 
  
    
      #hash  ⇒ Fixnum 
    
    
  
  
  
  
  
  
  
  
  
    
Generates a
Fixnumhash value for this object. - 
  
    
      #private_methods(all = true)  ⇒ Array 
    
    
  
  
  
  
  
  
  
  
  
    
Returns the list of private methods accessible to obj.
 - 
  
    
      #protected_methods(all = true)  ⇒ Array 
    
    
  
  
  
  
  
  
  
  
  
    
Returns the list of protected methods accessible to obj.
 - 
  
    
      #public_methods(all = true)  ⇒ Array 
    
    
  
  
  
  
  
  
  
  
  
    
Returns the list of public methods accessible to obj.
 - 
  
    
      #remove_instance_variable(symbol)  ⇒ Object 
    
    
  
  
  
  
  private
  
  
  
  
    
Removes the named instance variable from obj, returning that variable’s value.
 - 
  
    
      #respond_to?(symbol, include_private = false)  ⇒ Boolean 
    
    
  
  
  
  
  
  
  
  
  
    
Returns
true> if obj responds to the given method. - 
  
    
      #send  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Invokes the method identified by symbol, passing it any arguments specified.
 - 
  
    
      #singleton_method_added  ⇒ Object 
    
    
  
  
  
  
  private
  
  
  
  
    
Not documented.
 - 
  
    
      #singleton_method_removed  ⇒ Object 
    
    
  
  
  
  
  private
  
  
  
  
    
Not documented.
 - 
  
    
      #singleton_method_undefined  ⇒ Object 
    
    
  
  
  
  
  private
  
  
  
  
    
Not documented.
 - #singleton_methods ⇒ Object
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      #taint  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Marks obj as tainted—if the
$SAFElevel is set appropriately, many method calls which might alter the running programs environment will refuse to accept tainted strings. - 
  
    
      #tainted?  ⇒ Boolean 
    
    
  
  
  
  
  
  
  
  
  
    
Returns
trueif the object is tainted. - 
  
    
      #to_a  ⇒ Array 
    
    
  
  
  
  
  
  
  
  
  
    
Returns an array representation of obj.
 - 
  
    
      #to_s  ⇒ String 
    
    
  
  
  
  
  
  
  
  
  
    
Returns a string representing obj.
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      #type  ⇒ Class 
    
    
  
  
  
  
  
  
  
  
  
    
Deprecated synonym for
Object#class. - 
  
    
      #untaint  ⇒ Object 
    
    
  
  
  
  
  
  
  
  
  
    
Removes the taint from obj.
 
Methods included from Kernel
#Array, #Float, #Integer, #String, #abort, #at_exit, #autoload, #autoload?, #binding, #block_given?, #callcc, #caller, #catch, #chomp, #chomp!, #chop, #chop!, #eval, #exit, #fail, #format, #global_variables, #gsub, #gsub!, #iterator?, #lambda, #load, #local_variables, #loop, #method_missing, #proc, #raise, #rand, #require, #scan, #set_trace_func, #split, #sprintf, #srand, #sub, #sub!, #test, #throw, #trace_var, #trap, #untrace_var, #warn
Constructor Details
#initialize ⇒ Object (private)
Not documented
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      # File 'object.c', line 630
static VALUE
rb_obj_dummy()
{
    return Qnil;
}
     | 
  
Dynamic Method Handling
This class handles dynamic methods through the method_missing method in the class Kernel
Instance Method Details
#==(other) ⇒ Boolean #equal?(other) ⇒ Boolean #eql?(other) ⇒ Boolean
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
<i>obj</i> and <i>anObject</i> 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
  
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      # File 'object.c', line 93 static VALUE rb_obj_equal(obj1, obj2) VALUE obj1, obj2;  | 
  
#===(other) ⇒ Boolean
Case Equality—For class Object, effectively the same as calling  #==, but typically overridden by descendents to provide meaningful semantics in case statements.
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      # File 'object.c', line 45 VALUE rb_equal(obj1, obj2) VALUE obj1, obj2;  | 
  
#=~(other) ⇒ false
Pattern Match—Overridden by descendents (notably Regexp and String) to provide meaningful pattern-match semantics.
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      # File 'object.c', line 1071 static VALUE rb_obj_pattern_match(obj1, obj2) VALUE obj1, obj2;  | 
  
#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.
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      # File 'gc.c', line 1992
VALUE
rb_obj_id(VALUE obj)
{
    /*
     *                32-bit VALUE space
     *          MSB ------------------------ LSB
     *  false   00000000000000000000000000000000
     *  true    00000000000000000000000000000010
     *  nil     00000000000000000000000000000100
     *  undef   00000000000000000000000000000110
     *  symbol  ssssssssssssssssssssssss00001110
     *  object  oooooooooooooooooooooooooooooo00        = 0 (mod sizeof(RVALUE))
     *  fixnum  fffffffffffffffffffffffffffffff1
     *
     *                    object_id space
     *                                       LSB
     *  false   00000000000000000000000000000000
     *  true    00000000000000000000000000000010
     *  nil     00000000000000000000000000000100
     *  undef   00000000000000000000000000000110
     *  symbol   000SSSSSSSSSSSSSSSSSSSSSSSSSSS0        S...S % A = 4 (S...S = s...s * A + 4)
     *  object   oooooooooooooooooooooooooooooo0        o...o % A = 0
     *  fixnum  fffffffffffffffffffffffffffffff1        bignum if required
     *
     *  where A = sizeof(RVALUE)/4
     *
     *  sizeof(RVALUE) is
     *  20 if 32-bit, double is 4-byte aligned
     *  24 if 32-bit, double is 8-byte aligned
     *  40 if 64-bit
     */
    if (TYPE(obj) == T_SYMBOL) {
        return (SYM2ID(obj) * sizeof(RVALUE) + (4 << 2)) | FIXNUM_FLAG;
    }
    if (SPECIAL_CONST_P(obj)) {
        return LONG2NUM((long)obj);
    }
    return (VALUE)((long)obj|FIXNUM_FLAG);
}
     | 
  
#send(symbol[, args...]) ⇒ Object #__send__(symbol[, args...]) ⇒ Object
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"
  
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      # File 'eval.c', line 6098 static VALUE rb_f_send(argc, argv, recv) int argc;  | 
  
#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
  
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      # File 'object.c', line 156 VALUE rb_obj_class(obj) VALUE obj;  | 
  
#clone ⇒ 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.
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      # File 'object.c', line 215 VALUE rb_obj_clone(obj) VALUE obj;  | 
  
#dup ⇒ 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.
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      # File 'object.c', line 251 VALUE rb_obj_dup(obj) VALUE obj;  | 
  
#==(other) ⇒ Boolean #equal?(other) ⇒ Boolean #eql?(other) ⇒ Boolean
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
<i>obj</i> and <i>anObject</i> 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
  
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      # File 'object.c', line 93 static VALUE rb_obj_equal(obj1, obj2) VALUE obj1, obj2;  | 
  
#==(other) ⇒ Boolean #equal?(other) ⇒ Boolean #eql?(other) ⇒ Boolean
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
<i>obj</i> and <i>anObject</i> 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
  
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      # File 'object.c', line 93 static VALUE rb_obj_equal(obj1, obj2) VALUE obj1, obj2;  | 
  
#extend ⇒ Object
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"
  
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      # File 'eval.c', line 7665 static VALUE rb_obj_extend(argc, argv, obj) int argc;  | 
  
#freeze ⇒ Object
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
  
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      # File 'object.c', line 724 VALUE rb_obj_freeze(obj) VALUE obj;  | 
  
#frozen? ⇒ Boolean
Returns the freeze status of obj.
a = [ "a", "b", "c" ]
a.freeze    #=> ["a", "b", "c"]
a.frozen?   #=> true
  
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      # File 'object.c', line 748 static VALUE rb_obj_frozen_p(obj) VALUE 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.
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      # File 'gc.c', line 1992
VALUE
rb_obj_id(VALUE obj)
{
    /*
     *                32-bit VALUE space
     *          MSB ------------------------ LSB
     *  false   00000000000000000000000000000000
     *  true    00000000000000000000000000000010
     *  nil     00000000000000000000000000000100
     *  undef   00000000000000000000000000000110
     *  symbol  ssssssssssssssssssssssss00001110
     *  object  oooooooooooooooooooooooooooooo00        = 0 (mod sizeof(RVALUE))
     *  fixnum  fffffffffffffffffffffffffffffff1
     *
     *                    object_id space
     *                                       LSB
     *  false   00000000000000000000000000000000
     *  true    00000000000000000000000000000010
     *  nil     00000000000000000000000000000100
     *  undef   00000000000000000000000000000110
     *  symbol   000SSSSSSSSSSSSSSSSSSSSSSSSSSS0        S...S % A = 4 (S...S = s...s * A + 4)
     *  object   oooooooooooooooooooooooooooooo0        o...o % A = 0
     *  fixnum  fffffffffffffffffffffffffffffff1        bignum if required
     *
     *  where A = sizeof(RVALUE)/4
     *
     *  sizeof(RVALUE) is
     *  20 if 32-bit, double is 4-byte aligned
     *  24 if 32-bit, double is 8-byte aligned
     *  40 if 64-bit
     */
    if (TYPE(obj) == T_SYMBOL) {
        return (SYM2ID(obj) * sizeof(RVALUE) + (4 << 2)) | FIXNUM_FLAG;
    }
    if (SPECIAL_CONST_P(obj)) {
        return LONG2NUM((long)obj);
    }
    return (VALUE)((long)obj|FIXNUM_FLAG);
}
     | 
  
#id ⇒ Fixnum
Soon-to-be deprecated version of Object#object_id.
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      # File 'object.c', line 108 VALUE rb_obj_id_obsolete(obj) VALUE obj;  | 
  
#initialize_copy ⇒ Object
:nodoc:
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      # File 'object.c', line 267 VALUE rb_obj_init_copy(obj, orig) VALUE obj, orig;  | 
  
#inspect ⇒ String
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      # File 'object.c', line 391 static VALUE rb_obj_inspect(obj) VALUE obj;  | 
  
#instance_eval(string[, filename [, lineno]]) ⇒ Object #instance_eval {|| ... } ⇒ Object
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
  
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      # File 'eval.c', line 6729 VALUE rb_obj_instance_eval(argc, argv, self) int argc;  | 
  
#instance_of? ⇒ Boolean
Returns true if obj is an instance of the given class. See also Object#kind_of?.
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      # File 'object.c', line 428 VALUE rb_obj_is_instance_of(obj, c) VALUE obj, c;  | 
  
#instance_variable_defined?(symbol) ⇒ Boolean
Returns true if the given instance variable is defined in obj.
class Fred
  def initialize(p1, p2)
    @a, @b = p1, p2
  end
end
fred = Fred.new('cat', 99)
fred.instance_variable_defined?(:@a)    #=> true
fred.instance_variable_defined?("@b")   #=> true
fred.instance_variable_defined?("@c")   #=> false
  
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      # File 'object.c', line 2048 static VALUE rb_obj_ivar_defined(obj, iv) VALUE obj, iv;  | 
  
#instance_variable_get(symbol) ⇒ Object
Returns the value of the given instance variable, or nil if the instance variable is not set. The @ part of the variable name should be included for regular instance variables. Throws a NameError exception if the supplied symbol is not valid as an instance variable name.
class Fred
  def initialize(p1, p2)
    @a, @b = p1, p2
  end
end
fred = Fred.new('cat', 99)
fred.instance_variable_get(:@a)    #=> "cat"
fred.instance_variable_get("@b")   #=> 99
  
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      # File 'object.c', line 1986 static VALUE rb_obj_ivar_get(obj, iv) VALUE obj, iv;  | 
  
#instance_variable_set(symbol, obj) ⇒ Object
Sets the instance variable names by symbol to object, thereby frustrating the efforts of the class’s author to attempt to provide proper encapsulation. The variable did not have to exist prior to this call.
class Fred
  def initialize(p1, p2)
    @a, @b = p1, p2
  end
end
fred = Fred.new('cat', 99)
fred.instance_variable_set(:@a, 'dog')   #=> "dog"
fred.instance_variable_set(:@c, 'cat')   #=> "cat"
fred.inspect                             #=> "#<Fred:0x401b3da8 @a=\"dog\", @b=99, @c=\"cat\">"
  
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      # File 'object.c', line 2018 static VALUE rb_obj_ivar_set(obj, iv, val) VALUE obj, iv, val;  | 
  
#instance_variables ⇒ Object
#is_a? ⇒ Boolean #kind_of? ⇒ Boolean
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
  
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      # File 'object.c', line 472 VALUE rb_obj_is_kind_of(obj, c) VALUE obj, c;  | 
  
#is_a? ⇒ Boolean #kind_of? ⇒ Boolean
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
  
      472 473 474  | 
    
      # File 'object.c', line 472 VALUE rb_obj_is_kind_of(obj, c) VALUE obj, c;  | 
  
#method(sym) ⇒ Object
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"
  
      9095 9096 9097  | 
    
      # File 'eval.c', line 9095 static VALUE rb_obj_method(obj, vid) VALUE 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
  
      1869 1870 1871  | 
    
      # File 'object.c', line 1869 static VALUE rb_obj_methods(argc, argv, obj) int argc;  | 
  
#nil? ⇒ Boolean
call_seq:
nil.nil?               => true
<anything_else>.nil?   => false
Only the object nil responds true to nil?.
      1054 1055 1056  | 
    
      # File 'object.c', line 1054 static VALUE rb_false(obj) VALUE 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.
      1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030  | 
    
      # File 'gc.c', line 1992
VALUE
rb_obj_id(VALUE obj)
{
    /*
     *                32-bit VALUE space
     *          MSB ------------------------ LSB
     *  false   00000000000000000000000000000000
     *  true    00000000000000000000000000000010
     *  nil     00000000000000000000000000000100
     *  undef   00000000000000000000000000000110
     *  symbol  ssssssssssssssssssssssss00001110
     *  object  oooooooooooooooooooooooooooooo00        = 0 (mod sizeof(RVALUE))
     *  fixnum  fffffffffffffffffffffffffffffff1
     *
     *                    object_id space
     *                                       LSB
     *  false   00000000000000000000000000000000
     *  true    00000000000000000000000000000010
     *  nil     00000000000000000000000000000100
     *  undef   00000000000000000000000000000110
     *  symbol   000SSSSSSSSSSSSSSSSSSSSSSSSSSS0        S...S % A = 4 (S...S = s...s * A + 4)
     *  object   oooooooooooooooooooooooooooooo0        o...o % A = 0
     *  fixnum  fffffffffffffffffffffffffffffff1        bignum if required
     *
     *  where A = sizeof(RVALUE)/4
     *
     *  sizeof(RVALUE) is
     *  20 if 32-bit, double is 4-byte aligned
     *  24 if 32-bit, double is 8-byte aligned
     *  40 if 64-bit
     */
    if (TYPE(obj) == T_SYMBOL) {
        return (SYM2ID(obj) * sizeof(RVALUE) + (4 << 2)) | FIXNUM_FLAG;
    }
    if (SPECIAL_CONST_P(obj)) {
        return LONG2NUM((long)obj);
    }
    return (VALUE)((long)obj|FIXNUM_FLAG);
}
     | 
  
#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.
      1927 1928 1929  | 
    
      # File 'object.c', line 1927 static VALUE rb_obj_private_methods(argc, argv, obj) int argc;  | 
  
#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.
      1903 1904 1905  | 
    
      # File 'object.c', line 1903 static VALUE rb_obj_protected_methods(argc, argv, obj) int argc;  | 
  
#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.
      1951 1952 1953  | 
    
      # File 'object.c', line 1951 static VALUE rb_obj_public_methods(argc, argv, obj) int argc;  | 
  
#remove_instance_variable(symbol) ⇒ Object (private)
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
  
      1165 1166 1167  | 
    
      # File 'variable.c', line 1165 VALUE rb_obj_remove_instance_variable(obj, name) VALUE obj, name;  | 
  
#respond_to?(symbol, include_private = false) ⇒ Boolean
Returns true> if obj responds to the given method. Private methods are included in the search only if the optional second parameter evaluates to true.
      4207 4208 4209  | 
    
      # File 'eval.c', line 4207 static VALUE obj_respond_to(argc, argv, obj) int argc;  | 
  
#send(symbol[, args...]) ⇒ Object #__send__(symbol[, args...]) ⇒ Object
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"
  
      6098 6099 6100  | 
    
      # File 'eval.c', line 6098 static VALUE rb_f_send(argc, argv, recv) int argc;  | 
  
#singleton_method_added ⇒ Object (private)
Not documented
      630 631 632 633 634  | 
    
      # File 'object.c', line 630
static VALUE
rb_obj_dummy()
{
    return Qnil;
}
     | 
  
#singleton_method_removed ⇒ Object (private)
Not documented
      630 631 632 633 634  | 
    
      # File 'object.c', line 630
static VALUE
rb_obj_dummy()
{
    return Qnil;
}
     | 
  
#singleton_method_undefined ⇒ Object (private)
Not documented
      630 631 632 633 634  | 
    
      # File 'object.c', line 630
static VALUE
rb_obj_dummy()
{
    return Qnil;
}
     | 
  
#singleton_methods ⇒ Object
#taint ⇒ Object
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.
      661 662 663  | 
    
      # File 'object.c', line 661 VALUE rb_obj_taint(obj) VALUE obj;  | 
  
#tainted? ⇒ Boolean
Returns true if the object is tainted.
      643 644 645  | 
    
      # File 'object.c', line 643 VALUE rb_obj_tainted(obj) VALUE obj;  | 
  
#to_a ⇒ Array
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"]
  
      294 295 296  | 
    
      # File 'object.c', line 294 static VALUE rb_any_to_a(obj) VALUE 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.”
      313 314 315  | 
    
      # File 'object.c', line 313 VALUE rb_any_to_s(obj) VALUE obj;  | 
  
#type ⇒ Class
Deprecated synonym for Object#class.
      133 134 135  | 
    
      # File 'object.c', line 133 VALUE rb_obj_type(obj) VALUE obj;  | 
  
#untaint ⇒ Object
Removes the taint from obj.
      683 684 685  | 
    
      # File 'object.c', line 683 VALUE rb_obj_untaint(obj) VALUE obj;  |