Yield

---

• Blocks and Procs

examples/functions/yield.cr

def run
  puts "before"
  yield
  puts "after"
end

run {
  puts "in block"
}

run do
  puts "in do-end"
end

• Optionally you can add a &anything if you think that makes the code more readable, but the important part is having yield in the code.

examples/functions/yield_block.cr

def run(&block)
  puts "before"
  yield
  puts "after"
end

run {
  puts "in block"
}

• You can call yield more than once inside the function and the block will be executed for every yield.

examples/functions/twice.cr

def run
  puts "before"
  yield
  puts "middle"
  yield
  puts "after"
end

run {
  puts "in block"
}
puts "----"
run do
  puts "in do-end"
end