Chapter 15: Arrays, Maps, and Random Numbers

In this chapter, we will learn about Java arrays, which allow us to manipulate a potentially huge amount of data in an organized and efficient manner. We will also use a close Java relation to arrays, ArrayList, and look at the differences between them.

Once we are comfortable handling substantial amounts of data, we will see what the Android API has to offer to help us easily connect our newfound data-handling skills to the user interface without breaking a sweat.

The topics in this chapter include the following:

• The Random class
• Handling data with arrays
• Arrays mini-app
• Dynamic arrays including a mini-app
• Multidimensional arrays including a mini-app
• The ArrayList class
• The enhanced for loop
• The Java HashMap

First, let's learn about the Random class.