Question

在网上浏览关于ruby的互联网时，我看到super这个词。有人可以说出它是什么以及它能做什么吗？

Answer 1

super方法调用父类方法。

例如：

class A
  def a
    # do stuff for A
  end
end

class B < A
  def a
    # do some stuff specific to B
    super
    # or use super() if you don't want super to pass on any args that method a might have had
    # super/super() can also be called first
    # it should be noted that some design patterns call for avoiding this construct
    # as it creates a tight coupling between the classes.  If you control both
    # classes, it's not as big a deal, but if the superclass is outside your control
    # it could change, w/o you knowing.  This is pretty much composition vs inheritance
  end
end

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进一步学习

Answer 2

如果要使用继承，如果要从子类调用父类方法，我们使用super

c2.1.6 :001 > class Parent
2.1.6 :002?>   def test
2.1.6 :003?>     puts "am in parent class"
2.1.6 :004?>   end
2.1.6 :005?>  end
 => :test_parent 
2.1.6 :006 > 
2.1.6 :007 >   class Child < Parent
2.1.6 :008?>     def test
2.1.6 :009?>       super
2.1.6 :010?>     end
2.1.6 :011?>   end
 => :test_parent 
2.1.6 :012 > Child.new.test
am in parent class
 => nil 
2.1.6 :013 >

我们可以通过不同的方式使用super（例如：super，super（））。

Answer 3

它用于实现当前方法的超类实现。在方法体内，调用super就像调用原始方法一样。搜索方法体开始于发现包含原始方法的对象的超类。

database.getConnection()

Answer 4

Ruby使用super关键字来调用当前方法的超类实现。在方法体内，调用super就像调用原始方法一样。搜索方法体在对象的超类中开始，该对象被发现包含原始方法。

def url=(addr)
  super (addr.blank? || addr.starts_with?('http')) ? addr : http://#{addr}
end

什么是Ruby中的“超级”？

4 个答案: