Blocks In-depth: Calling Blocks

block_given.rb

def log
  if block_given?
    puts "before block"
    yield
    puts "after block"
  end
end

log # nothing will be displayed!

call_block.rb

def log
  puts "before block"
  yield
  puts "after block"
end

log do
  puts "o hai"
end

provide_block.rb

some_method(some_argument) do
  # block content goes here
end