Commodore Plus 4 - Page 146

seconds, in case you need something counted, or something must be
done a certain number of limes (such as printing).
The loop variable is the variable that is added to or subtracted from
during the FOR/NEXT loop. The start value and the end value are the
beginning and ending counts for the loop variable.
The logic of the FOR statement is as follows: First, the loop variable is
set to the start value. When the program reaches a line with the com
mand NEXT, it adds the STEP increment (default = 1) to the value of
the loop variable and checks to see if it is higher than the end of loop
vaiue. If it is not higher, the next line executed is the statement im
mediately following the FOR statement. If the loop variable is larger
than the end of loop number, then the next statement executed is the
one following the NEXT statement. See also the NEXT statement.
EXAMPLE:
10 FOR L - 1 TO 10
20 PRINT L
30 NEXT L
40
PRINT "I'M DONE! L - "L
This program prints the numbers from one to ten on the screen, fol
lowed by the message I'M DONE! L = 11.
The end of loop value may be followed by the word STEP and another
number or variable. In this case, the value following the STEP is added
each time instead of one. This allows you to count backwards, by frac
tions, or any way necessary.
You can set up loops inside one another. This is known as nesting
loops. You must be careful to nest loops so that the iast loop to start is
the first one to end.
EXAMPLE OF NESTED LOOPS:
10 FOR L - 1 TO 100
20 FOR A - 5 TO 11 STEP 2
30 NEXT A
40NEXTL
\
This FOR... NEXT
loop is "nested" in
side the larger one.
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