#######################类变量######################class Cloud    @@count=0    def initialize(user,password,ip)        @user =    user        @password    =password        @ip    =ip    end    def createvm        @ip    =ip        @@count+=1    endend##########################类方法和实例方法#########################class Example    def instance_method        puts "instance_method"    end    def Example.class_method        puts "class class_method"    endende1 = Example.new()e1.instance_methodclass MyLogger    private_class_method :new    @@logger = nil##类变量    def MyLogger.create        @@logger = new unless @@logger            @@logger        end    endend