Language Guide

G L O S S A R Y
367
item A value in a list or record. An item is
specified by its offset from the beginning or
end of the list or record.
labeled parameter A parameter that is
identified by a label. See also positional
parameter.
list An ordered collection of values.
Lists are enclosed by braces. The values in
a list are separated by commas. List is an
AppleScript value class.
literal expression An expression that
evaluates to itself.
local variable A variable that is available
only in the handler in which it is defined.
Variables that are defined within
subroutines, command handlers, and error
handlers are local unless they are explicitly
declared as global variables.
loop A series of statements that is
repeated.
looping variable A variable whose value
controls the number of times the statements
in a Repeat statement are executed.
Middle Element reference form A
reference form that specifies the middle
object of a particular class in a container.
Name reference form A reference form
that specifies an object by the value of its
Name property.
nested control statement A control
statement that is contained within another
control statement.
Number A synonym for the AppleScript
value classes Integer and Real.
object An identifiable part of an
application, or thing within an application,
that can respond to commands.
object class A category for objects that
share characteristics such as properties
and element classes and respond to the
same commands.
operand A value from which an operator
derives another value.
operation An expression that derives a
new value from one or more other
values. An operator, such as the addition
operator (+), concatenation operator (&),
or Contents Of, determines how the new
value is derived.
operator An AppleScript language element
(a word, series of words, or symbol) used in
an expression to derive a value from
another value or pair of values.
optional parameter A parameter that
need not be included for a command to
be successful.
parameter variable An identifier in a
subroutine definition that represents the
actual value of a parameter when the
subroutine is called. Also called formal
parameter.
parent script object A script object from
which another script object, called the child,
inherits properties and handlers.
partial reference A reference that does not
include enough information to identify
an object or objects uniquely. When
AppleScript encounters a partial reference,
it uses the default object specified in the Tell
statement to complete the reference.