HP 48g Graphing Calculator - Manual (Page 418)

Loop structures let a program execute a sequence of commands several
times. To specify in advance horn' many times to repeat the loop, use a
definite loop. To use a test to determine whether or not to repeat the
loop, use an indefinite loop.
START...NEXT
Loop Structures
Enter this structure into a program by pressing fPRG) B K C H
T. Its syntax is;
.start finish S T F loop-clause N E K l
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START...NEXT executes the loop-clause sequence of commands one
time for each number in the range start to finish. The loop-clause is
alwfa,ys executed at least once.
START takes two numbers {start and finish) from the stack and stores
them as the starting and ending values for a loop counter. Then, the
loop-clause is executed. NEXT increments the counter by 1 and tests
to see if its value is less than or equal to finish. If so, the loop-clause
is executed again—otherwise, execution resumes following NEXT.
START-STEP
Enter this structure into a program by pressing (PRGl EFiCH
®ST A R T . Its syntax is:
■ s ... .start finish S T A R T loop-clause
increment S T E P ... s -
START...STEP executes the loop-clause sequence just like
START...NEXT does—except that the program specifies the
increment value for the counter, rather than incrementing by 1. The
loop-clause is always executed at least once.
START takes two numbers {start and finish) from the stack and stores
them as the starting and ending values of the loop counter. Then
the loop-clause is executed. STEP takes the increment value from
the stack and increments the counter by that value. If the argument
of STEP is an algebraic or a name, it’s automatically evaluated to a
number.
The increment value can be positive or negative. If it’s positive, the
loop is executed again if the counter is less than or equal to finish. If
29-12 Programming the HP 48