How to Program a TI-83 Plus/Inputs

Using the Prompt function

Let's start with a fairly primitive command. Prompt is a basic function that prompts you to input a value into one of the 27 possible variables (the 26 letters of the alphabet + theta (θ)). You can find it as the 2nd command in the "I/O" section.

:Prompt θ
:Disp "YOU CHOSE",θ

This can be made to make some simple math programs, for example:

:Prompt A
:Prompt B
:Disp √(A2+B2)

This is a small program that can do the Pythagorean theorem. See if you can make a program for something else math-related, like the area of a shape!

The Prompt function is great, but what if you want to say a message when asking someone for a variable?

Using the Input function

Input is a more complex command, but still very easy to learn. It works like this:

:Input "NUMBER: ",A

That's it! That's all you need to do to use input. There's also one other thing you can do with the Input function; strings.

Note: String variables

If you press the VARS button, you'll be met with a menu. If you go down to the bottom, you'll be met with the string variables. These can be used to store strings, which normal variables can't. Back to the Input function now!

If you ask a Prompt command to use a string variable, it won't be able to, but Input will use it just like it would any other variable.

:Input "STRING: ",Str1
:Disp "YOU SAID",Str1,"AND WE SAY NO!"

Conclusion

Input and Prompt are the ways to make your programs truly interactive.

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