Method taking an argument or a block

Question

Is it possible to write a method that acts differently depending on the type of input? I'm trying to write one that acts like this

hello("derick")
#=> "hello derick!"

hello do
  "derick"
end
#=>"<hello>'derick'<hello/>"

Answer 1

Yes, it is possible in Ruby. Using block_given? you can check if a block is passed and execute the block else return any other result.

def hello(s=nil)
  if block_given?
    "<hello>'#{yield}'</hello>"
  else
    "hello #{s}"
  end
end

puts hello("derick!")

puts (hello do
  "derick"
end)

HTH