Accessors : getter setter « Class « Ruby

Home
Ruby
1.ActiveRecord
2.Array
3.CGI
4.Class
5.Collections
6.Database
7.Date
8.Design Patterns
9.Development
10.File Directory
11.GUI
12.Hash
13.Language Basics
14.Method
15.Network
16.Number
17.Rails
18.Range
19.Reflection
20.Statement
21.String
22.Threads
23.Time
24.Tk
25.Unit Test
26.Windows Platform
27.XML
Ruby » Class » getter setter 




Accessors


# Ruby simplifies the creation of getters and setters with a little metaprogramming and the methods attr, attr_reader, attr_writer, and attr_accessor, all from the Module class

# By supplying the attr method, Ruby provides a way to quickly create the equivalent of six lines of code with a single line.

# The method attr creates a single getter method, named by a symbol, with an optional setter method (if the second argument is true)


#!/usr/bin/env ruby

class Dog
  attr :bark, true
end

Dog.instance_methods - Object.instance_methods # => ["bark""bark="]

dog = Dog.new

dog.bark="Woof!"
puts dog.bark # => Woof!


# single line attr :bark, true is equivalent to writing out the bark and bark= methods in six lines of code:

class Dog

  def bark
    @bark
  end

  def bark=(val)
    @bark = val
  end

end

 














Related examples in the same category
1.Add a method named get_color, which returns the color of animal objects created from this class:
2.Call a member method
3.getter and setter
4.Define getter for a attribute
5.Make an attribute readable and writable by using attr_reader, attr_writer
6.Provide the getter
7.Setter with calculation
8.Setter with =
java2s.com  | Contact Us | Privacy Policy
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.