In class 1 we defined the instance variables and we saw how difficult to accessing it. We managed to access it via calling methods that initializing it.
So we can simplify it by defining access methods.
class Test def initialize @one = 1 end def get_one @one end end
The ‘get_one’ method is the reader method for reading the instance variable value.
Ruby has shortcut for this.
class Test attr_reader :one def initialize @one = 1 end end
These accessor methods are identical to the methods we wrote by hand earlier.
Sometimes we need to modify the value of these variables from outside. how we do that?
At first we can do this by hand:
class Test def initialize @one = 1 end def one=(new_value) @one = new_value end end
The above code allows us to call ‘equal to’ sign on the objects method. This is the setter method. We can set a value to @one like:
t = Test.new t.one = 3 t.one => 3
Ruby also provides a shortcut for this. It is: ‘attr_writer’, so rewrite the above code:
class Test attr_writer :one def initialize @one = 1 end end
Most of the cases we needed ‘attr_reader’ and ‘attr_writer’. So the code becomes:
class Test attr_reader :one attr_writer :one def initialize @one = 1 end end
We can again simplify the above code!
class Test attr_accessor :one def initialize @one = 1 end end
How is it? Nice. is n’t it?