Commodore VIC-20 - Page 42

NEXT
Format: Abbreviation: Screen Display:
NEXT [variable , variable N JfrljE N f"
, . . . , variable]
This statement compleies a loop that was started by a FOR
statement. If the word NEXT is not followed by a variable nameh the
loop completed is the last one thai was started. If there is a variable
name given, that loop is finished. If the loop being finished wasn't
the last one started, any loops between the last one and the one
specified in the NEXT statement are lost.
Care must be taken when placing loops within other loops, to
complete them properly. Here is an example of correct placement
("nesting'*) of loops. r-
EXAMPLE 1:
10 FOR L = 1 TO 100
20 FOR M = 1 TO 10
30 NEXT M
40 NEXT L
Notice that the first loop finished is the last one that was started.
Here are some general examples of the NEXT statement.
EXAMPLE 2:
i
NEXT
NEXT
J
NEXT I, J, K
ON
Formats: Abbreviation: Screen Display:
ON variable GOTO number [, number number]
ON variable GOSUB number [, number number]
This statement allows the program to choose from a list o1 line
numbers to go to. If the variable has a value of 1, the first line
number is the one chosen. If the value is 2, the second number in
the list is used, and so on. If the value in the variable is less than 1 or
greater than the number of line numbers in the list, the program just
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