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...
p obj.instance_variable_set("@foo",1)# => 1 p obj.instance_variable_set(:@foo,2)# => 2 p obj.instance_variable_get(:@foo)# => 2
4 因为涉及到安全问题,所以最好禁用eval()方法. 5 可以用$SAFE全局变量设置安全级别(0-4).当安全级别大于0时,ruby会拒绝执行污染的字符串. 6 有两个方法可以操作实例变量:Object#instance_variable_get()方法和Object#instance_variable_set()方法. 7 钩子方法 1classString2defself.inherited(subclass)3puts"#...
使用eval有时候并不是一个好办法,会影响整体代码的可读性和维护性,因此我们使用class_eval以及实例变量set和get方法来实现这个方法。class Person end def add_checked_attribute(klass, attribute) klass.class_eval do define_method "#{attribute}=" do |value| instance_variable_set("@#{attribute}", value)...
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...
Instance Variables¶ ↑VALUE rb_iv_get(VALUE obj, const char *name) Retrieve the value of the instance variable. If the name is not prefixed by ‘@’, that variable shall be inaccessible from Ruby. VALUE rb_iv_set(VALUE obj, const char *name, VALUE val) Sets the value of the ...
Set breakpoints. Run a program with the debugger. At the breakpoint, enter the debugger console. Use debug commands. Evaluate Ruby expressions (e.g. p lvar to see the local variable lvar). Query the program status (e.g. info to see information about the current frame). Control program...
ConditionVariable#wait Queue#pop, SizedQueue#push Thread#join Kernel#sleep Process.wait IO#wait, IO#read, IO#write and related methods (e.g. #wait_readable, #gets, #puts and so on). IO#select is not supported. This example program will perform several HTTP requests concurrently: ...
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...
@开头:实体变量,实例变量 (Instance variable)。 @@开头:类别变量,类变量 (Class variable)。 大写字母开头:常数 (Constant)。 已经定义的类可以在运行时修改 Ruby是动态语言,你可以在程序中修改先前定义过的类。 也可以在某个类的实例中定义该实例特有的方法,这叫做单例方法。