Course: Kotlin Fundamentals for Mobile Development

Since 2019 Kotlin has been designated as the official programming language for Android development. However, Kotlin can be used for more than just mobile application development. Kotlin supports server-side development, full-stack development, data science, native application development, and multiplatform development. Kotlin compiles to Java bytecode, runs on the Java Virtual Machine, and can interoperate with existing Java code in your projects. In this course, you will be introduced to the Kotlin programming language. You will discover various use cases for Kotlin and identify when you would choose to use Kotlin over Java. You will use the Kotlin online playground to write your first bit of code, run Kotlin on the Java Virtual Machine (JVM), and compile Kotlin code to JavaScript. Next, you will use the Kotlin command line compiler on your local machine and run the Kotlin REPL (read-evaluate-print-loop) interactive environment to work with Kotlin code. Finally, you will install the IntelliJ integrated development environment to work with Kotlin and create and run your first Kotlin project.

Kotlin supports the same basic concepts as other high-level programming languages such as Java and C#. However, Kotlin has a unique, more concise syntax than these languages and also has some additional features which make programming in Kotlin more robust and secure. In this course, you will learn to work with basic Kotlin data types and syntax. You will explore how to make a choice between val-type variables and var-type variables and the details of how to use those in your code. You will also use string templates to evaluate expressions embedded in strings. Next, you will work with conditional branching using if-else statements and expressions. You will perform multiple conditional checks using when statements and expressions, work with collection data structures such as lists, sets, and maps, and use looping constructs such as for-loops, while loops, and do-while loops. Finally, you will explore null safety features in Kotlin such as null-safe invocations, not-null assertions, and the Elvis operator.

Kotlin supports functional and object-oriented programming constructs. Functions in Kotlin are first-class citizens and function objects can be treated just like other data types. In addition, Kotlin supports very concise function expressions called lambdas that are very often used with collection-related operations. In this course, you will learn the structure, syntax, and features of basic functions in Kotlin. You will learn to define default values for function input parameters, use named and positioned parameters with functions, and create functions with variable numbers of arguments. Next, you will work with higher-order functions. You will learn to pass in functions as input arguments to other functions and return functions as return values from functions. You will also implement and use closures in your code. Finally, you will define and use lambda expressions which are short, concise function definitions for use and throw functions. You will learn how to use the trailing lambda syntax in Kotlin and practice creating and using lambda expressions with collections.

A core feature of Kotlin is its ability to interoperate with Java code. Classes and objects in Kotlin are built on the same principles as in Java but Kotlin has additional features that improve upon Java's object-oriented model, including the ability to implement enum classes, sealed classes, data classes, and extension functions for third-party classes. In this course, you will be introduced to classes and objects in Kotlin. You will learn to define and use primary constructors, secondary constructors, and initializer blocks. You will also see how you can define custom getters and setters for class properties. Next, you will learn how you can inherit from classes in Kotlin and implement interfaces. You will study the implementation and use of functional interfaces and other special classes that Kotlin supports, such as enum classes, sealed classes, data classes, and companion objects. Finally, you will see how you can use extension functions to extend third-party class functionality and use coroutines for asynchronous programming.

Android application development remains highly relevant due to the widespread use of Android devices and the increasing demand for mobile applications. With the growing reliance on smartphones and tablets for various tasks, from communication and entertainment to productivity and e-commerce, Android apps play a vital role in meeting the evolving needs and preferences of users. In this course, you will embark on a journey to explore the essential concepts of Android development. You will learn about the four crucial components of Android applications - activities, services, broadcast receivers, and content providers. You will grasp the significance of the Android manifest file and gain familiarity with the fundamental architectural principles that will govern the development of robust Android applications. Next, you will learn how to set up and install Android Studio. You will create and configure an Android Views project and you will recognize the importance of selecting the appropriate Android API level to ensure compatibility and maximize the potential of your application. By exploring the various directories and folders within an Android project, you will gain a comprehensive understanding of their roles and functions. Finally, you will dive into the practical aspects of Android development by creating an Android Virtual Device (AVD) within Android Studio. This AVD will enable you to execute and evaluate your applications directly within the development environment. You will run your first application, fine-tune the layout, and manipulate the included resources, providing you with hands-on experience in developing apps using Android Studio.

Views and layouts are essential in Android applications as they determine the visual presentation, user interaction, and overall user experience, enabling developers to create intuitive and visually appealing interfaces that adapt to different device sizes and orientations. In this course you will learn the basics of using layouts or ViewGroups to design your application's screen. You will create screens using TextViews, EditText widgets, and ImageViews. Next, you will improve the look and feel of your application by including a MaterialToolbar to display the app title and other actions. You will also see how you can incorporate and wire up a floating action button in your app. Furthermore, you will explore listeners in more detail by developing a simple counter application that also includes a Snackbar for notifications. Finally, you will expand your skills in Android app development by exploring different layout options, including the linear, relative, frame, and constraint layouts.

Interactive dynamic layouts such as GridView and ListView in Android enable developers to present data in a visually appealing and interactive manner. These views leverage adapters as a bridge between the data source and the layout, allowing for improved performance using view recycling. In this course, we will create dynamic views using GridView and ListView layouts. We learn how to recycle views within the layouts, optimizing performance and memory usage by reusing existing views. Furthermore, we will explore formatting the layouts to utilize cards, enhancing the visual presentation of the content. Next, we will explore a variety of commonly used widgets in mobile applications. We will create an autocomplete text view, providing users with suggestions and auto-completion functionality for efficient input. We'll also create multi-autocomplete text views, empowering users to select multiple suggestions. We will also incorporate a ScrollView to allow users to navigate and view content that extends beyond the screen size. Finally, we will incorporate a toggle switch into our app, allowing users to easily switch between two states or options. We will create a ListView with checkboxes, enabling users to select multiple items from a list. Additionally, we will utilize the toggle button for state selection and create a screen with a popup menu, providing users with a visually organized menu of options or actions.

Intents, activities, and fragments are essential components in Android development as they enable seamless navigation between screens, facilitate modular and reusable code structures, and allow for efficient communication and data transfer within an Android application. In this course, we will begin by exploring the functionality of intents in Android applications. Through hands-on exercises, we will learn to navigate between activities using intents, incorporating both implicit and explicit intents. We will also leverage intents to direct users to external web pages, enhancing the flow and navigation within our applications. Next, we will delve into advanced techniques in Android app development. We will set up the user interface for a reservations app and utilize intents to navigate to the reservations page, implementing view manipulation code to accept and display reservations. We will create view binding objects to streamline the process of accessing views. Additionally, we will use data binding to specify data directly within XML layouts for seamless integration. Then we will enhance list handling capabilities by leveraging RecyclerView. Finally, we will modularize our app by dividing it into fragments and pass input arguments to fragments for customization. We will learn to dynamically add and replace fragments using the fragment manager and fragment transactions and explore backstack management, enabling smooth back navigation within our app. To facilitate effective communication between activities and fragments, we will utilize ViewModel architecture, enhancing data exchange and interaction.

Final Exam: Kotlin Fundamentals will test your knowledge and application of the topics presented throughout the Kotlin Fundamentals track.