Ruby On Rails 面试题与答案

Question: How can you implement method overloading in Ruby on Rails?

This one�s a tricky question. If you have a background in Java then you must know that method overloading is simply multiple methods with same name but different signatures/parameters.

In the case of Ruby method overloading is not supported. 

However, it does support the overall goal of passing variable number of parameters to the same method. You would implement it like this:

class MyClass  
  def initialize(*args)  
    if args.size < 2  || args.size > 3  
      puts 'This method takes either 2 or 3 arguments'  
    else  
      if args.size == 2  
        puts 'Found two arguments'  
      else  
        puts 'Found three arguments'  
      end  
    end  
  end  
end  

The output can be seen here:

MyClass.new([10, 23], 4, 10)  
Found three arguments
MyClass.new([10, 23], [14, 13]) 
Found two arguments

SO: You can get the same effect as method overloading but you just have to manage the number of variables inside your method itself.