Calculator User Manual

292 Chapter 17: Programming
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 292 of 40
A string is a sequence of characters enclosed in "quotes". In
programming, strings allow the program to display information or
prompt the user to perform some action. For example:
Disp "The result is",answer
— or —
Input "Enter the angle in degrees",ang1
— or —
"Enter the angle in degrees”
!
str1
Input str1,ang1
Some input commands (such as
InputStr
) automatically store user
input as a string and do not require the user to enter quotation
marks.
A string cannot be evaluated mathematically, even if it appears to be
a numeric expression. For example, the string
"61"
represents the
characters
"6"
and
"1"
, not the number
61
.
Although you cannot use a string such as
"61"
or
"2x+4"
in a
calculation, you can convert a string into a numeric expression by
using the
expr
command.
String Operations
Strings are used to enter and display text characters. You can
type a string directly, or you can store a string to a variable.
How Strings Are
Used