Atari XL User Manual

32
The Ateri XL Handbook
specified using the command STE P. Try changing
line 10 to:
10 FOR COUNT = 0 TO 30 STEP 3
Then RUN the program again. COUNT is now
increased by 3 each time the loop is repeated. The
STEP can also be negative, so that the numbers
get smaller:
10 FOR COUNT = 50 TO 0 STEP -2.5
In summary, the instructions are used like this:
FOR V = X TO Y STEP Z
is used to begin a loop (V is a variable and X, Y and
Z may be variables or numbers), and
NEXT V
marks the end of the loop. Note that, unlike some
other microcomputer BASICs, in Atari BASIC the
variable must be specified after NEXT.
The variables used in FOR ... NEXT loops must be
simple numeric variables; string variables, and
elements of arrays may not be used.
Nested Loops
FOR ... NEXT loops can be nested - that is, one
loop can be contain one or more other loops. Here is
an example:
10 FOR A = 1 TO 3
20 FOR B = 1 TO 4
30 PRINT A, B
40 NEXT B

Atari XL Specifications

General

Brand	Atari
Model	XL
Category	Desktop
Language	English