how to avoid passing same parameter through multiple function :     def function1(a)
      #some computation
      function2(a, b)
    end
    
    def function2(a,b)
      #some computation
      function3(a, b, c)
    end
    
    def function3(a, b ,c)
      print a
    end

How to avoid passing same parameter (a) to all function. One way is to make parameter 'a' as instance variable. what is the right way to do this. 