Conditionals

have_coins = false
if have_coins
  print "Got coins"
else
  print "No coins"

have_coins = false
if have_coins
  print "Got coins"
else
  print "No coins"

A short syntax for single statements can also be used:

have_coins = false
if have_coins then print "Got coins" else print "No coins"

have_coins = false
if have_coins then print "Got coins" else print "No coins"

Because if statements can be used as expressions, this can also be written as:

have_coins = false
print if have_coins then "Got coins" else "No coins"

have_coins = false
print if have_coins then "Got coins" else "No coins"

Conditionals can also be used in return statements and assignments:

is_tall = (name) ->
  if name == "Rob"
    true
  else
    false

message = if is_tall "Rob"
  "I am very tall"
else
  "I am not so tall"

print message -- prints: I am very tall

is_tall = (name) ->
  if name == "Rob"
    true
  else
    false

message = if is_tall "Rob"
  "I am very tall"
else
  "I am not so tall"

print message -- prints: I am very tall

The opposite of if is unless:

unless os.date("%A") == "Monday"
  print "it is not Monday!"

unless os.date("%A") == "Monday"
  print "it is not Monday!"

print "You're lucky!" unless math.random! > 0.1

print "You're lucky!" unless math.random! > 0.1

In Expression

You can write range checking code with an in-expression.

a = 5

if a in [1, 3, 5, 7]
  print "checking equality with discrete values"

if a in list
  print "checking if `a` is in a list"

a = 5

if a in [1, 3, 5, 7]
  print "checking equality with discrete values"

if a in list
  print "checking if `a` is in a list"