ruby_block_example.rb

# Function prints results of block execution
# and prints message if no block was given
def function_that_can_accept_block(x, &block)
  return "Wow, no block was given!" unless block_given?
  block.call(x)
end

def some_other_function(x)
  "I am a function and I print my input: #{x}"
end

# this will print an error message
p function_that_can_accept_block(1)

# this will print current time
p function_that_can_accept_block(Time.now) {|x| some_other_function(x)}