Apple iWork '09 - Manual (Page 36)

Value Types
A function argument has a type, which specifies what type of information the
argument can contain. Functions also return a value of a particular type.
Value Type Description
any If an argument is specified as “any,” it can be a
Boolean value, date/time value, duration value,
number value, or string value.
Boolean A Boolean value is a logical TRUE (1) or FALSE
(0) value or a reference to a cell containing or
resulting in a logical TRUE or FALSE value. It is
generally the result of evaluating a Boolean
expression, but a Boolean value can be specified
directly as an argument to a function or as the
content of a cell. A common use of a Boolean
value is to determine which expression is to be
returned by the IF function.
collection An argument that is specified as a collection can
be a reference to a single table cell range, an
array constant, or an array returned by an array
function. An argument specified as collection will
have an additional attribute defining the type of
values it can contain.
date/time This is a date/time value or a reference to a
cell containing a date/time value in any of the
formats supported by iWork. If a date/time value
is typed into the function, it should be enclosed
in quotation marks. You can choose to display
only a date or time in a cell, but all date/time
values contain both a date and a time.
Although dates can usually be entered directly
as strings (for example, “12/31/2010”), using the
DATE function insures the date will be interpreted
consistently regardless of the date format
selected in System Preferences (search for “date
format” in the System Preferences window).
36 Chapter 2 Overview of the iWork Functions