Question

Hello I’m trying to learn ruby blocks. But I have a trouble to get over this construction:

class SomeApp

  attr_accessor :load_listener

  def on_load(&block)
    @load_listener = block
  end

  def load(x)
    @load_listener.call(x) if @load_listener
  end

end

app = SomeApp.new
app.on_load { |x| puts 'on load #{x}'} 
app.load(5)

I don’t understand why result of this code is ‘on load #{x}’, instead of ‘on load 5’
Any help is appreciated.

Answer 1

You’re using single quotes (') instead of double quotes ("). String interpolation (#{...}) does only work with double quotes.

Change puts 'on load #{x}' to puts "on load #{x}".