App Inventor Logo

Let's Build an APP

Hi-Lo A classic Number guessing Game


AppInventor provides procedure and function block definitions which can greatly increase the readability of code.

We conside procedures or functions when we can identify code that needs to be used more than once - it is BAD coding to type it again when it can be promoted to a module

Procedures are wrappers for bunches of commands:


Functions typically return with a value that can then be used


Notice the 2 examples above - "newgame" is now a callable collection of commands, it contains a "call" to a "makerandom" function included below. Procedures and functions must be CALLED, can have parameters (as many as you want) and can access global variables or use local variables - quite powerful really).

hilo Done

Now let's explore OTHER FEATURES