Ruby的include和extend
在ruby中基本上有三种引入module的方式?
一、在类定义中引入module后，module中的方法成为类的实例方法。?
在类定义中用include引入module。?
例如：?
Ruby代码?
module Base?
def test?
p "This is a instance method!"?
end?
end?
class Car?
include Base?
end?
Car.new.test => "This is a instance method!"?
module Base
def test
p "This is a instance method!"
end
end
class Car
include Base
end
Car.new.test => "This is a instance method!"
二、在类定义中引入module后，module中的方法成为类的类方法。?
在类定义中用extend引入module。?
例如：?
Ruby代码?
?
module Base?
def test?
p "This is a instance method!"?
end?
end?
class Car?
extend Base?
end?
Car.test => "This is a class method!"?
module Base
def test
p "This is a instance method!"?
end
end
class Car
extend Base
end
Car.test => "This is a class method!"
三、在类定义中引入module后，module中的方法即有成为类的实例方法，又有成为类的类方法。?
这需要在类定义中引入module时，用include。?
例如：?
Ruby代码??
module Base?
def test?
p "This is a instance method!"?
end?
def self.included(base)?
def base.call?
p "This is a class method---call"?
end?
base.extend(ClassMethods)?
end?
module ClassMethods?
def hello?
p "This is a class method----hello"?
end?
end?
end?
class Car?
include Base?
end?
Car.new.test => "This is a instance method!"?
Car.call => "This is a class method---call"?
Car.hello => "This is a class method---hello"?
module Base
def test
p "This is a instance method!"
end
def self.included(base)
def base.call
p "This is a class method---call"
end
base.extend(ClassMethods)
end
module ClassMethods
def hello
p "This is a class method----hello"
end
end
end
class Car
include Base
end
Car.new.test => "This is a instance method!"
Car.call => "This is a class method---call"
Car.hello => "This is a class method---hello"
参考资料：?
1、http://developer.51cto.com/art/200907/132919.htm?
2、http://juixe.com/techknow/index.php/2006/06/15/mixins-in-ruby/?
