Owner's manual

Page 21-60

To avoid an infinite loop, make sure that start_value < end_value.

Example – calculate the summation S using a FOR…NEXT construct

The following program calculates the summation

Using a FOR…NEXT loop:

« 0 → n S « 0 n FOR k k SQ S + ‘S‘ STO NEXT S “S” →TAG » »

Store this program in a variable @@S2@@. Verify the following exercises: J

3 @@@S2@@ Result: S:14 4 @@@S2@@ Result: S:30

5 @@@S2@@ Result: S:55 8 @@@S2@@ Result: S:204

10 @@@S2@@ Result: S:385 20 @@@S2@@ Result: S:2870

30 @@@S2@@ Result: S:9455 100 @@@S2@@ Result: S:338350

You may have noticed that the program is much simpler than the one stored in

@@@S1@@. There is no need to initialize k, or to increment k within the program. The

program itself takes care of producing such increments.

The FOR…STEP construct

The general form of this statement is:

start_value end_value FOR loop_index program_statements

increment STEP

The start_value, end_value, and increment of the loop index can be positive

or negative quantities. For increment > 0, execution occurs as long as the

index is less than or equal to end_value. For increment < 0, execution

occurs as long as the index is greater than or equal to end_value. Program

statements are executed at least once (e.g.,

1 0 START 1 1 STEP returns 1)

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