User`s guide

E-Prime User’s Guide
Chapter 4: Using E-Basic
Page 128
Essentially, properties store information regarding the behavior or physical appearance of the
object. For instance, a TextDisplay object has a Text property, which represents the text to be
displayed on the screen.
Object.Methods
Objects also expose internal routines for programmability called methods. In E-Basic, an object
method can take the form of a command or a function.
Object.Commands
Commands are quite literally the action or actions that the object can perform. An object
command is referenced using the object.command syntax. Commands may or may not take
parameters. For example, the Clear command (i.e., object.Clear), which may be used to clear
the active display, requires no parameters, while the Rectangle command associated with the
Canvas object requires parameters to define the position and size of the rectangle to be drawn.
Note, not all commands are available to all objects. Refer to the E-Basic Online Help for a listing
of commands available to each object.
Object.Functions
An object method which returns a value is called a function. An object function is invoked using
the object.function syntax. Functions may or may not take parameters. For example, the Mean
function (i.e., object.Mean) requires no parameters to return the mean of a collection of values
contained within a Summation object. However, the GetPixel function associated with the Canvas
object requires parameters in order to return the color value at a particular x, y coordinate
position.
4.2.2 Getting Help
The E-Basic Online Help is launched through the Start button (i.e., select E-Basic Help from the
E-Prime menu), or through the Help menu in E-Studio. The E-Basic Help command opens the
Help Topics dialog, containing Contents, Index and Find tabs.
4.2.2.1 Contents
The Contents page lists a table of contents for the Help topics available within the E-Basic Online
Help system. The main Help topics are displayed as books, which may be opened to display
related subtopics. The topics within the Contents list may be expanded or collapsed by double
clicking the book. When a topic is expanded, information concerning individual subtopics may be
displayed by double-clicking the desired item.
4.2.2.2 Index
The Index page displays an alphabetical listing of topics and commands within E-Basic. This is
typically the best way to find a command or function name. The Help information for a particular
topic may be displayed by selecting the topic and clicking the Display button, or by double-
clicking the topic. The topics may be searched by typing directly in the first field of the Help
Topics dialog, or by scrolling through the topics contained in the index using the scroll bar on the
right side of the Help Topics dialog.