动态设置类变量所使用到的方法为:class_variable_set和class_variable_get。 实例: classPerson(1..3).eachdo|num|class_variable_set("@@name_#{num}".to_sym,num*3)enddefinitialize(1..3).eachdo|num|instance_variable_set("@name_#{num}".to_sym,self.class.class_variable_get("@@name_#{num...
在方法内部,使用instance_variable_set方法来设置实例变量。 下面是一个示例代码: 代码语言:ruby 复制 class MyClass def self.set_instance_variable_from_string(string) instance_variable_set("@my_variable", string) end def self.get_instance_variable @my_variable end end MyClass.set_instance_vari...
p obj.instance_variable_set("@foo",1)# => 1 p obj.instance_variable_set(:@foo,2)# => 2 p obj.instance_variable_get(:@foo)# => 2
class_eval do define_method "#{attribute}=" do |value| instance_variable_set("@#{attribute}", value) end define_method attribute do instance_variable_get "@#{attribute}" end end end add_checked_attribute(Person, :age) add_checked_attribute(Person, :sex) me = Person.new me.age = 18...
A setter method is one which sets, or changes, the value of a variable belonging to a particular object. Alright, let’s check in on yourusername. If my math is correct, it should be set to“coolgirl2002”right now. julia.username#NoMethodError: undefined method `username' for #<User:...
由于两种方法非常常用,Ruby 定义了attr_accessor :variable_name、attr_reader :variable_name、attr_writer :variable_name三种属性声明方法。其中:accessor=reader+writer。 同时注意:变量名前一定要带:,变量名之间要用,分割。 实例方法 实例方法的定义与其他方法的定义一样,都是使用def关键字,但它们只能通过类实例来...
Here we use Ruby’sinstance_variable_getmethod to read an instance variable with an arbitrary name, andinstance_variable_setto assign a new value to it. Unfortunately the variable name must be prefixed with an “@” sign in both cases—hence the string interpolation. ...
This is a new C-API set to exchange a raw memory area, such as a numeric array and a bitmap image, between extension libraries. The extension libraries can share also the metadata of the memory area that consists of the shape, the element format, and so on. Using these kinds of metad...
You can write down the definition of classes and modules: methods defined in the class, instance variables and their types, and inheritance/mix-in relations. The goal of RBS is to support commonly seen patterns in Ruby programs and it allows writing advanced types including union types, method...
An instance variable set within a before validator is accessible within the endpoint's code and can also be utilized within the rescue_from handler. class TwitterAPI < Grape::API before do @var = 1 end get '/' do puts @var # => 1 raise end rescue_from :all do puts @var # => ...