For [Code Block, Proc, Lambda, and Closure in Ruby]()

yield_block.rb

def burger
  puts 'top bun'
  yield if block_given?
  puts 'bottom bun'
end

burger do
  puts 'lettuce'
  puts 'tomato'
  puts 'chicken breast'
end

# the above code will prints out
# top bun
# lettuce
# tomato
# chicken breast
# bottom bun