I just learned Ruby within the past month, and am working on my TDD skills with RSpec.
I am trying to get the following test to pass:
it "has a modified color" do
@phone.color = "green"
puts @phone.color.should == "green"
end
Here is my code:
class Phone
attr_reader :name
attr_reader :manufacturer
attr_accessor :color
def initialize(name, manufacturer)
@name = name
@manufacturer = manufacturer
end
def color(color='black')
@color = color
end
end
I am trying to do the following essentially:
phone = Phone.new("Moto X", "Motorola")
puts phone.color # 'black'
phone.color = "green"
puts phone.color # 'green'
However, it is still outputting 'black' after I try reassigning the color to green, please help.
Thanks.
The problem is that your def color is an attribute reader not a writer. So it will always return the default color, black, per the parameter.
When you do the assignment:
phone.color = "green"
It is calling the implicit writer (generated by attr_accessor :color). An attribute writer would look like:
def color=(c)
@color = c
end
After writing the color to 'green', you attempt to access via:
puts phone.color
This will execute the attribute reader:
def color(c='black')
@color=c
end
Which sets the color to 'black' and returns that color.
If you want a default black color, you can define your class like this:
class Phone
attr_reader :name
attr_reader :manufacturer
attr_accessor :color # This generates your reader and writer methods
def initialize(name, manufacturer)
@name = name
@manufacturer = manufacturer
end
def color
@color || 'black' # If @color is nil, return 'black', otherwise @color
end
end
2.0.0-p195 :012 > phone = Phone.new("Moto X", "Motorola")
=> #<Phone:0x9ecc1ac @name="Moto X", @manufacturer="Motorola">
2.0.0-p195 :013 > phone.color
=> "black"
2.0.0-p195 :014 > phone.color = "green"
=> "green"
2.0.0-p195 :015 > phone.color
=> "green"