Texas Instruments TI-89, TI-92

Chapter 17: Programming 297

17PROGRM.DOC TI-89/TI-92 Plus: Programming (English) Susan Gullord Revised: 02/23/01 1:14 PM Printed: 02/23/01 2:18 PM Page 297 of 40

To enter most of the loop-related

commands, use the Program

Editor’s „ Control toolbar menu.

When you select a loop, the loop

command and its corresponding

End command are inserted at the

cursor location.

:For

:EndFor

You can then begin entering the commands that will be executed in

the loop.

A For...EndFor loop uses a counter to control the number of times

the loop is repeated. The syntax of the For command is:

For(variable, begin, end [, increment])

When For is executed, the variable value is compared to the end

value. If variable does not exceed end, the loop is executed;

otherwise, program control jumps to the command following EndFor.

:For i,0,5,1

: --------

:EndFor

:--------

At the end of the loop (EndFor), program control jumps back to the

For command, where variable is incremented and compared to end.

Using Loops to Repeat a Group of Commands

To repeat the same group of commands successively, use a

loop. Several types of loops are available. Each type gives you

a different way to exit the loop, based on a conditional test.

„ Control Toolbar

Note: A loop command

marks the start of the loop.

The corresponding

End

command marks the end of

the loop.

For...EndFor Loops

Note: The ending value can

be less than the beginning

value, but the increment

must be negative.

Note: The

For

command

automatically increments th

counter variable so that the

program can exit the loop

after a certain number of

repetitions.

added to the counter each subsequent time

For is executed (If this optional value is

omitted, the increment is 1.)

exits the loop when

variable

exceeds this value

counter value used the first time For is executed

variable used as a counter

If the loop requires

arguments, the cursor is

positioned after the command.

i  5i > 5