[contents]
[prev] [next] [top] [bottom] (10 out of 17)
Operator Precedence
Table 2-3 summarizes the
precedence of ScriptX operators and expressions. Operators
higher up the table are evaluated first if they occur
side-by-side in an expression. Operators in the same table
cell have equal precedence and are evaluated from left to
right, unless otherwise stated.
Table 2-3: ScriptX operator precedence, highest
to lowest
Operator (s)
|
Notes
|
---|
collection[key]
|
element access in collections, described on page 50
|
object.variable
|
class and instance variable access, described in Chapter 3
|
function arg arg . . .
function (arg, arg, . . .)
|
function calls, described in Chapter
3
|
object as class
|
object coercion, described in Chapter
3
|
-
|
negation, described on page
42
|
* /
|
multiplication, division, described on page 42
|
+ -
|
addition, subtraction, described on page 42
|
= == <> != !== > < >= <=
contains
|
equality and magnitude, described on page 43.
contains
is used for collection membership, described on page 52
|
not
|
logical not, described on page
47.
|
and
|
logical and, described on page
47
|
or
|
logical or, described on page
47.
|
in
by
|
for expressions association is from right to left.
|
|
|
pipe operator, described in Chapter
5
|
repeat guard
exit
for
return
|
loops and block control expressions are described in Chapter 4, while the
guard expression is described in Chapter 8.
|
&
|
thread operator, described in Chapter
5
|
location := value
|
assignment operator, described on page 38
|
You can change the order of evaluation by surrounding
expressions with parentheses. ScriptX evaluates the innermost
expressions first:
(((3 + 15) * 2) == 36)
(3 < 4) and (5 >= 2)
For additional information on operators and expression syntax,
see Appendix A, "ScriptX Reference."
This document is part of the ScriptX Language Guide, one of the volumes of the ScriptX Technical Reference Series. ScriptX is developed by the ScriptX Engineering Team at Apple Computer, successor to the Kaleida Engineering Team at Kaleida Labs, Inc.
Copyright 1996 Apple Computer, Inc. All Rights Reserved.