Atari XL

28 The A tar; XL Handbook
The variables must have commas separating them
in the INPUT command. If you press RETURN
before entering all the items the XL will print
another question mark and wai t for the remaining
items. When you type in the information you must
use a comma to separate numeric entries, or press
RETURN to mark the end of each string entry (a
comma would be counted as part of the string). If
you enter too many items the surplus ones will be
ignored.
Let's use what we know about variables and
INPUT to improve the area program. Clear the
computer's memory by typing NEW (RETURN),
and then type in this program.
10 REM IMPROVED AREA PROGRAM
20 PRINT
" " "
30 PRINT
"ENTER
WIDTH" ;
40 INPUT
WIDTH
50 PRINT
"ENTER
HEIGHT";
60 INPUT HEIGHT
70
AREA = WIDTH
*
HEIGHT
80 PRINT: PRINT
"AREA
=
" .
AREA
,
This program will read the two numbers you type
in for width and height and print the area of the
rectangle. Using INPUT has made the program
much more flexible: we don't have to alter the
program to use different numbers.
REMARKS
Line 10 of the last program is a remark or comment
statement. These are used to hold comments, notes
and titles to make the purpose of a program and the
way in which it works clear to someone reading the
listing. Remarks are identified by the word REM
before the remark and have no effect when the
program is RUN.