在Ruby中,单例模式可以通过使用模块或类来实现。这里有两种方法来初始化单例模式:
方法1:使用模块
module Singleton def self.included(base) base.class_eval do @instance = nil def self.instance @instance ||= new end def self.new(*args, &block) raise "Singleton class can't be instantiated" end end end end class MyClass include Singleton def initialize(name) @name = name end end my_instance1 = MyClass.instance my_instance2 = MyClass.instance puts my_instance1.object_id == my_instance2.object_id # 输出 true,表示两个实例是同一个对象
方法2:使用类变量
class SingletonClass @@instance = nil def self.instance @@instance ||= new end def self.new(*args, &block) raise "Singleton class can't be instantiated" end end class MyClass < SingletonClass def initialize(name) @name = name end end my_instance1 = MyClass.instance my_instance2 = MyClass.instance puts my_instance1.object_id == my_instance2.object_id # 输出 true,表示两个实例是同一个对象
这两种方法都可以实现单例模式,确保一个类只有一个实例,并提供一个全局访问点。