MIT App Inventor

Blocks Section

The Blocks Section in MIT App Inventor is extremely important. This is where we can create the logic and each components behaviours. There are 2 distinct columns:

1. Blocks: This is where you can create the logic and each components behaviours.
2. Viewer: Drag the blocks you want from the Blocks column to the Viewer.

More Detail in the Blocks Section

The Blocks section consists of 3 distinct sections that will go into more detail in the cheat sheet which I will give out later:

• Built-in Blocks: Are blocks available for all the components you have chosen.

• Screen x: Are blocks available for the components available in that certain screen only.

• Any Components: These are the rest of the components that is not part of any screen.

Types of Blocks Available

Blocks can be split into three groups:

1. Built-in Blocks: Blocks that are available to use for all components.
   

2. Screen Components Blocks: Blocks that are available to use for components in that screen only.
   

3. Any Components Blocks: Blocks that are available for any component that is not in any Screens.
   

More emphasis on Build-In Blocks

Built-In Blocks as stated above are blocks that are available for all components to use, there are many types of Built-In Components that you can choose from which are extremely important in the field of Computer Science too:

a. Control Blocks: If you need one component’s action to work under one condition or need one action to work repeatedly.

b. Logic Blocks: If you want to set a component’s action to true or false or you may need to use other AND/OR statements

c. Math Blocks: If you need to use mathematical operations for a component to work. (Note on ^ - this means a power)

d. Text Blocks: If you need to change a component’s text while the app is running, use this!

e. List Blocks: Sometimes you may require making lists of certain things, so if you want you can use list blocks.

f. Dictionary Blocks: If you want to associate a value to a word. (i.e., 1 = a, 2 = b and I choose 1 so I got a), use this (we normally do not use it as this is more advanced!)

g. Colour Blocks: If you want to change a component’s colour while the app is running use this!

h. Variables Blocks: if you want to set a name for a certain part of the part use this.

i. Procedure Blocks: If you want to put a sequence of blocks into one use this.

Download the Cheat Sheet in by clicking this Link for more information about Built-In blocks.

Created by: Ryan Orimaco