Skip to Main Content
App Inventor
book

App Inventor

by David Wolber, Hal Abelson, Ellen Spertus, Liz Looney
May 2011
Beginner to intermediate content levelBeginner to intermediate
386 pages
11h 41m
English
O'Reilly Media, Inc.
Content preview from App Inventor

Chapter 1. Hello Purr

image with no caption

This chapter gets you started building apps. It presents the key elements of App Inventor—the Component Designer and the Blocks Editor—and leads you through the basic steps of creating your first app, HelloPurr. When you’re finished, you’ll be ready to build apps on your own.

A typical first program with a new computer system prints the message “Hello World” to show that everything is connected correctly. This tradition goes back to the 1970s and Brian Kernighan’s work on the C programming language at Bell Labs (Brian is now a visiting scholar at Google working on the App Inventor team!). With App Inventor, even the simplest apps do more than just show messages: they play sounds and react when you touch the phone. So we’re going to get started right away with something more exciting; your first app (as shown in Figure 1-1) will be “HelloPurr,” a picture of a cat that meows when you touch it and purrs when you shake it.

The HelloPurr app

Figure 1-1. The HelloPurr app

What You’ll Learn

The chapter covers the following topics:

  • Building apps by selecting components and then telling them what to do and when to do it.

  • Using the Component Designer to select components. Some components are visible on the phone screen and some aren’t.

  • Adding media (sounds and images) to apps by uploading them from ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Hello App Inventor!

Hello App Inventor!

Carl Simmons, Paula Beer
App Inventor 2 Essentials

App Inventor 2 Essentials

Felicia Kamriani, Krishnendu Roy
App Inventor 2, 2nd Edition

App Inventor 2, 2nd Edition

David Wolber, Hal Abelson, Ellen Spertus, Liz Looney

Publisher Resources

ISBN: 9781449306786Supplemental ContentErrata Page