```coffeescript
grade = (student, period=(if b? then 7 else 6), messages={"A": "Excellent"}) ->
  if student.excellentWork
    "A+"
  else if student.okayStuff
    if student.triedHard then "B" else "B-"
  else
    "C"

square = (x) -> x * x

two = -> 2

math =
  root:   Math.sqrt
  square: square
  cube:   (x) -> x * square x

race = (winner, runners...) ->
  print winner, runners

class Animal extends Being
  constructor: (@name) ->

  move: (meters) ->
    alert @name + " moved #{meters}m."

hi = `function() {
  return [document.title, "Hello JavaScript"].join(": ");
}`

heredoc = """
CoffeeScript subst test #{ 010 + 0xf / 0b10 + "nested string #{ /\n/ }"}
"""

###
CoffeeScript Compiler v1.2.0
Released under the MIT License
###

OPERATOR = /// ^ (
?: [-=]>             # function
) ///
```

Use valid CoffeeScript in example
user
```coffeescript
grade = (student, period=(if b? then 7 else 6), messages={"A": "Excellent"}) ->
  if student.excellentWork
    "A+"
  else if student.okayStuff
    if student.triedHard then "B" else "B-"
  else
    "C"

square = (x) -> x * x

two = -> 2

math =
  root:   Math.sqrt
  square: square
  cube:   (x) -> x * square x

race = (winner, runners...) ->
  print winner, runners

class Animal extends Being
  constructor: (@name) ->

  move: (meters) ->
    alert @name + " moved #{meters}m."

hi = `function() {
  return [document.title, "Hello JavaScript"].join(": ");
}`

heredoc = """
CoffeeScript subst test #{ 0o010 + 0xf / 0b10 + "nested string #{ /\n/ }"}
"""

###
CoffeeScript Compiler v1.2.0
Released under the MIT License
###

OPERATOR = /// ^ (
?: [-=]>             # function
) ///
```
assistant