8.5

Table Of Contents
Box1.Append(IntVar)
Here, the Text Box object named "Box1" is the object into which we want the Append
function to place the value represented by IntVar. This function is an example of an
object function that returns a value.
Here's an example of an object function that returns a value:
MyVariable = Box1.IsVisible()
In this expression, the IsVisible function checks to see whether the object named "Box1"
is visible, then it puts the Boolean result (either "true" or "false") into the variable named
MyVariable.
In addition to interactive objects, some object functions let you access other kinds of
objects. For example:
MyVariable = Number.Sqrt(2)
The Number object is simply a library of math functions, rather than an interactive object.
This expression tells the Number object's Sqrt function to calculate the square root of two
and store the result into the variable named "MyVariable."
To refer to an object in an expression, that object must follow certain naming conventions.
It may not begin with a number, and it may not contain any symbols other than a dollar
sign ($) or an underscore (_). If it contains spaces, you can substitute underscores for them
when you refer to it in an expression.
Using the Expression Editor dialog box
The Expression Editor button displays the Expression Editor dialog box. You can use
this dialog box to create expressions in two ways:
If you are new to expressions, you can build them by double-clicking items in the lists in
the top half of the dialog box in the proper order.
If you are familiar with expression syntax, you can enter your expressions directly into
the large editing field.
320 | A GUIDE TO QUARKXPRESS 8.5: PLUS EDITION
INTERACTIVE LAYOUTS