/usr/bin/ruby -w#定义类classBox#构造器方法definitialize(w,h)@width,@height=w,hend#实例方法默认是 public 的defgetAreagetWidth()*getHeightend#定义 private 的访问器方法defgetWidth@widthenddefgetHeight@heightend#make them privateprivate:getWidth, :getHeight#用于输出面积的实例方法defprintArea@area=...
在类内部定义的实例变量，但在名为class instance variable的实例方法外部定义。Scope defines where in a...
You may get different resolution result after this change. Please report such cases to RubyGems/Bundler issues RubyGems still uses Molinillo resolver in Ruby 3.2. We plan to replace it with PubGrub in the future. Other notable changes since 3.1 Data New core class to represent simple immutable...
1 # 基本形式 2 irb(main):029:0> dict = {'cat'=>'cat1', 'dog'=>'dog1'} 3 => {"cat"=>"cat1", "dog"=>"dog1"} 4 # key必须为字符串或者标志 5 irb(main):030:0> dict2 = {cat=>cat1} 6 NameError: undefined local variable or method `cat' for main:Object 7 Did you...
instance_variable_get(var) ruby 1.8 特性 取得并返回对象的实例变量的值. 可以使用字符串或者Symbol来向var指定实例变量名. 若实例变量尚未定义,则返回nil. 1 2 3 4 5 6 7 8 9 10 classFoo definitialize @foo=1 end end obj = Foo.new
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...
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"#{self} was inherited by #{subclass}"4end5end6classMyString < String ;end#=> String was inherited by MyString ...
class User def initialize(name:, age:) @name, @age = name, age end attr_reader :name, :age end User.new(name: "John", age: 20) An example output: $ typeprof test.rb # Classes class User attr_reader name : String attr_reader age : Integer ...
Normal Object-oriented Features (e.g. class, method calls) Advanced Object-oriented Features (e.g. mix-in, singleton-method) Operator Overloading Exception Handling Iterators and Closures Garbage Collection Dynamic Loading of Object Files (on some architectures) Highly Portable (works on many Unix...
Scope of an instance variable isInstance variables cannot be altered except for some methods, and it's distinct to each object of a class.Class VariableClass variables are shared by all instances of a Ruby class. If one object instance changes the value of a class variable, that new value ...