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Playing with instance variables
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| require 'pry' | |
| require 'rspec' | |
| # Not using class variables | |
| class PersonNoVar | |
| @counter = 0 | |
| class << self | |
| attr_accessor :counter | |
| end | |
| def initialize | |
| self.class.counter += 1 | |
| end | |
| def self.count | |
| counter | |
| end | |
| end | |
| class StudentNoVar < PersonNoVar | |
| end | |
| ## Using Class Variables | |
| class Person | |
| @@counter = 0 | |
| def initialize | |
| @@counter += 1 | |
| end | |
| def self.count | |
| @@counter | |
| end | |
| end | |
| class Student < Person | |
| end | |
| describe 'counter' do | |
| context 'with class variables' do | |
| subject do | |
| 5.times { Person.new } | |
| 3.times { Student.new } | |
| end | |
| it 'works' do | |
| expect { subject }.to change { Person.count }.by(8) | |
| end | |
| end | |
| context 'without class variables' do | |
| subject do | |
| 5.times { PersonNoVar.new } | |
| 3.times { StudentNoVar.new } | |
| end | |
| it 'works' do | |
| expect { subject }.to change { PersonNoVar.count }.by(8) | |
| end | |
| end | |
| end |
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