Variables, operators, canvas, and multimedia Dr. José M. Reyes Álamo

2 Outline Variables Operators Canvas

Variables

4 Properties and variables In general the memory is a set of cells or slots, like spread sheet, where we store data. Properties and variables are named memory slots –What is the difference? We use variables and properties to store information used within our app.

5 An example Variable definition Name the variable Assign initial value Using the variable within an event handler Set a value Get the value cost=0 profit=0 price=0 On Button1.Click cost=7 profit=5 price=cost + profit Label1.text = price

6 Variables on AppInventor Numeric Variables: – Numeric Variables: –

Operators

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9 Reference Arithmetic operators and other math blocks – Logic operators –

Canvas

11 Canvas is a pixels grid Reference: basic.html#Canvas basic.html#Canvas

12 This class assignments Brainstorming about final project Reading Assignment: –AppInventor CH15 (Software Engineering and Debugging)AppInventor CH15 (Software Engineering and Debugging) –AppInventor CH17 (Creating Animated Apps)AppInventor CH17 (Creating Animated Apps) READING ASSIGNMENT EVALUATION: –Complete the reading assignments and answer the RA8_AppInventorCh15andCh17on Blackboard.

13 To have credit for each app you develop You should create a page for each application, containing the following: 1.A description about what the app does 2.A picture of the main screen 3.A picture of the Blocks diagram 4.Show your app running to your Professor Take a look a these examples: – – Additionally, you could add more pictures and write about your experience while developing your app.