Reliably detect types of Javascript objects and primitive values, easing polymorphic programming in JS

type-detective.coffee

#
# Helper module to reliably find the types of Javascript objects
# and primitive values, easing polymorphic programming.
#
# See also:
# * http://javascript.info/tutorial/type-detection
# * https://gist.github.com/olange/514325f6fe3d89610d224d731a2def9e
exp = module.exports = {}

#
# Returns the value of the hidden [[Class]] property of the given
# object; this property exists in all JavaScript native objects.
#
# Returns following values:
# * `"[object Array]"` for an instance of an `Array`
# * `"[object Date]"` for a Date object
# * `"[object Boolean]"` for a boolean primitive value
# * `"[object String]"` for a String object
# * `"[object Number]"` for an int or float primitive value
# * `"[object Null]"` for `null` and `undefined`
#
# Beware: works for `null` and `undefined` on Node.js, but
# would return the `window` object when running in a browser.
#
exp.classOf = (obj) ->
  {}.toString.call( obj)

# eof