9.3

Variables can be very useful. You can use a variable to store information such as the number
of the last page someone visited in a presentation, the end user's name, or the number of
points scored in a game.
Variable names are case-insensitive.
Operators
Operators are symbols (such as + and -) that let you add, subtract, multiply, divide, and
perform many other kinds of operations.
The most important operator is the equals sign, because it enables you to assign a value
to a variable. In the previous example, we could have used the following simple expression
to store the number 6 into the variable IntVar:
IntVar = 6
This expression tells an interactive presentation to store the value after the equals sign
into the variable named "IntVar."
Other operators let you combine or compare numbers and other values. For example:
IntVar = 2 + 4
This example uses two operators: The equals sign and the plus sign. When this expression
is executed, your interactive presentation adds 2 + 4 and puts the result into IntVar.
Use a single equals sign (=) for assignment, and a double equals sign (==) to check values
for equality.
Functions
Functions are commands that let you perform complex operations. Many kinds of functions
exist, but all of them use the same format:
FunctionName()
Some functions require you to put an "argument" (a parameter or variable) in the
parentheses after the function name, and others require you to leave the parentheses
empty. You should always include the parentheses, regardless of whether they contain
anything.
Functions that require parameters
Some functions require you to put a parameter or variable into their parentheses. When
you insert a parameter or variable into a function's parentheses, it's called "passing" that
parameter or variable to the function. For example:
Box1.Append(IntVar)
In this expression, the value of the variable IntVar is passed to the function Append. The
Append function, in turn, operates on that parameter by placing it in the Text Box object
named "Box1".
A GUIDE TO QUARKXPRESS 9.3 | 329
INTERACTIVE LAYOUTS