Book Image

Android Studio Arctic Fox Essentials - Kotlin Edition

By : Neil Smyth
Book Image

Android Studio Arctic Fox Essentials - Kotlin Edition

By: Neil Smyth

Overview of this book

Android Studio is an Integrated Development Environment based on the JetBrains IntelliJ IDEA. It offers developers a unique platform to design and develop Android apps using various developer tools. Fully updated for Android Studio Arctic Fox, the goal of this book is to teach the skills necessary to develop Android-based applications using the Kotlin programming language. This book begins with an outline of the steps necessary to set up an Android development and testing environment, followed by an introduction to programming in Kotlin which includes data types, control flow, functions, lambdas, and object-oriented programming. An overview of Android Studio covers areas such as tool windows, the code editor, and the layout editor tool. An introduction to the architecture of Android is followed by an in-depth look at the design of Android applications and user interfaces using the Android Studio environment. Early chapters detail Android architecture components such as view models, lifecycle management, Room database access, the Database Inspector, app navigation, live data, and data binding. More advanced topics such as intents are also covered, as are touch screen handling, gesture recognition, and the recording and playback of audio. This edition of the book also covers printing, transitions, cloud-based file storage, and foldable device support. The concepts of material design are also discussed in detail, including the use of floating action buttons, Snackbars, tabbed interfaces, card views, navigation drawers, and collapsing toolbars. Other key features of Android Studio Arctic Fox and Android taught in this book include the Layout Editor, the ConstraintLayout and ConstraintSet classes, MotionLayout Editor, view binding, constraint chains, barriers, and direct reply to notifications. Chapters also explore more advanced features of Android Studio such as app links, dynamic delivery, Gradle build configuration, and submitting apps to the Google Play developer console.
Table of Contents (93 chapters)
93
Index

15.10 Higher-order Functions

On the surface, lambdas and function references do not seem to be particularly compelling features. The possibilities that these features offer become more apparent, however, when we consider that lambdas and function references have the same capabilities of many other data types. In particular, these may be passed through as arguments to another function, or even returned as a result from a function.

A function that is capable of receiving a function or lambda as an argument, or returning one as a result is referred to as a higher-order function.

Before we look at what is, essentially, the ability to plug one function into another, it is first necessary to explore the concept of function types. The type of a function is dictated by a combination of the parameters it accepts and the type of result it returns. A function which accepts an Int and a Double as parameters and returns a String result for example is considered to have the following function...