Exercise 2: On Class Methods

Practice using class variables and class methods.

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Class methods

Like class variables, methods can be defined at the class level. Such methods are called class methods.

Class methods are defined by prepending the method name with self.. For example, in the following code snippet, greet is a class method.

class Person
 def self.greet()
  puts "Hello World!"
 end
end

The self keyword refers to the class itself. So, to call the class method, it has to be invoked on the class and not on a class instance. For example:

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Write a Counter class. It should have a count class method that displays the number of Counter objects created so far.

With your definition, consider the following code:

  puts Counter.count
  
  Counter.new
  puts Counter.count

It’s expected to print:

0
1

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