Getting input from the user and displaying output, I/o toolbar menu, Input commands – Texas Instruments PLUS TI-89 User Manual

Page 318

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Chapter 17: Programming 301

17PROGRM.DOC TI-89/TI-92 Plus: Programming (English) Susan Gullord Revised: 02/23/01 1:14 PM Printed: 02/23/01 2:18 PM Page 301 of 40

To enter most of the commonly
used input/output commands, use
the Program Editor’s …

I/O

toolbar

menu.

To see a submenu that lists
additional commands, select

1:Dialog

.

Command

Description

getKey

Returns the key code of the next key pressed. See
Appendix B for a listing of key codes.

Input

Prompts the user to enter an expression. The
expression is treated according to how it is entered.
For example:

¦

A numeric expression is treated as an
expression.

¦

An expression enclosed in "quotes" is treated as
a string.

Input

can also display the Graph screen and let the

user update the variables

xc

and

yc

(

rc

and

q

c

in

polar mode) by positioning the graph cursor.

InputStr

Prompts the user to enter an expression. The
expression is always treated as a string; the user
does not need to enclose the expression in "quotes".

PopUp

Displays a pop-up menu box and lets the user select
an item.

Prompt

Prompts the user to enter a series of expressions. As
with

Input

, each expression is treated according to

how it is entered.

Request

Displays a dialog box that prompts the user to enter
an expression.

Request

always treats the entered

expression as a string.

Getting Input from the User and Displaying Output

Although values can be built into a program (or stored to
variables in advance), a program can prompt the user to enter
information while the program is running. Likewise, a program
can display information such as the result of a calculation.

I/O Toolbar Menu

Input Commands

Tip: String input cannot be
used in a calculation. To
convert a string to a numeric
expression, use the expr
command.

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