Types
*****

Comefrom0x10 has two types of variables, strings and numbers. The space operator coerces its operands to strings, where ``undefined`` becomes the empty string::

   2 2 # prints 22
   'foo' undefined # prints "foo"

And mathematical operators coerce ``undefined`` to zero::

   2 + undefined # prints 2

.. note::
   
   As in early JavaScript, ``undefined`` is not reserved, it's a perfectly fine variable name.

Being strongishly typed, however, Cf0x10 doesn't try to make sense of nonsensical operations like adding strings to numbers::

   2 + 2 # prints 4
   2 + '2' # prints nothing

In the second line, the result of adding a string to a number is ``undefined``, so, as seen in :doc:`02-variables`, it prints nothing at all.

Lists
=====

As any Lisper knows, all data structures are just fancy forms of lists. In recent decades, however, a new movement, stringly-typed programming, has discovered that all lists are just fancy forms of strings. Cf0x10 embraces this movement, though there is a proposal to add list support, :doc:`../contributing/cum002-lists`.

Truthiness
==========

As in C, Cf0x10 has no boolean type. Numbers are good enough::

   0 # zero is falsy
   1 # all other numbers are truthy
   '' # empty strings are falsy
   'false' # non-empty strings are truthy
   1 / 0 # undefined is falsy

Next, we'll exercise Cf0x10's full complement of boolean operators to unlock this power.