Ruby here_and_there_4 - Understanding attr_accessor in a ruby Class

Understanding attr_accessor in a ruby Class


Below is a simple example for using attr_accessor in a ruby class.


attr_accessor is the property of an object. So, if server is a Class, the server's hostname can be is it's attribute or Property.


In the below example,


We are creating a class called "Person". Realistically, a Person can have a name, so name is a property or attribute of a person. Our object is a human being who belongs to a class called "Person", this object has a name, i.e. in real world A person with a name.


By using a Person's name (Object.attribute) you can address or call him ot greet him. This greeting or calling or addressing is called "Method" in ruby world ( only for this example's sake).




Let's walk thorugh the example


vim class.rb


class Person
      attr_accessor :name
     def greet

           #{@name} says hello
     end
end

attr_accessor is the Property of the object.


So, I create an Object with the Class.


Class here is "Person"


joe = Person.new


An object by the name "joe" is created.


:name is one of the attributes of the object "joe"


joe.name = "Tribiani"


Then we use this "Object.Attribute i.e. joe(object).name(attribute)" with a method.


Did we write any method i.e. function in the Class ? Yes we have i.e. is "greet"


So we call "Object.Attribute.Method" i.e. joe(object).name(attribute).greet(Method or Function)


How the output is seen


irb(main):001:0> require 'class.rb' # Ruby script written above
=> true
irb(main):002:0> joe = Person.new
=> #<0xb7c73cf8>
irb(main):003:0>

irb(main):003:0> joe.name="Tribiani" # Setting the name attribute for the object "joe"=> "Tribiani"

irb(main):004:0> joe.greet # joe(object).name(attribute).greet(Method or Function)=> "Tribiani says hello"
irb(main):005:0>