Kotlin at a glance

Use of Lambdas and higher-order functions to write more concise, clean, reusable, and simple code

Swati Saxena

• Publisher: BPB Publications
• Year: 2019
• eBook ISBN: 9789388511490
• Topic: Computer Science
• Subtopic: Operating Systems
• Index: Computer Science

Basic guide to develop an App in Android by using Kotlin Key Features

• Comprehensive coverage of all the concepts of Kotlin
• Simple language, crystal clear approach, user friendly book
• Concepts are duly supported by several examples and self-explanatory analogies.

Description
"Kotlin at a Glance" is a book that gives an in-depth knowledge about Kotlin. This book mainly focused on Kotlin programming language and its comparison to Java. By reading this book, the readers can make themselves familiar with the language's most important features and aspects.With a complete overview of OOPs, null safety, generics, and many other interesting features, this book is a perfect choice for fresher and experienced Java developers who want to learn more about this alternative JVM language.For reading this book, there's no need for any prior Kotlin knowledge, as the basics are explained in the book. Moreover, the required functional programming concepts are also described.The readers of this book will also learn to develop an app in android using Kotlin. Moreover, this book is for everyone who is on their way of becoming a developer. What will you learn

• Introduction to OOP, Java, Kotlin
• Kotlin Architecture, Token, Input, Operator, Array, Function
• Looping / Control Flow / Iteration
• Null Safety, Kotlin Lambda Functions and Exception Handling
• Constructor, Inheritance, Abstract Keyword, Polymorphism
• Collection, Coroutines, Generics
• Regex, Interoperability with Java, Android
• Who this book is for
  This book will prove to be a "must-have" for beginners as well as experienced professionals as it is a stepping stone for learning the technology. Table of Contents
  1. OOP in Brief
  2. An Introduction to Java
  3. An Introduction to Kotlin
  4. Kotlin Architecture
  5. Kotlin Token
  6. Kotlin Input
  7. Kotlin Operator
  8. String Operations
  9. Conditional Statements
  10. Jumping Statement
  11. Looping / Control Flow / Iteration
  12. Kotlin Array
  13. Null Safety
  14. Kotlin Function
  15. Function Scope
  16. Kotlin Lambda Functions and Exception Handling
  17. Kotlin OOPs
  18. Constructor
  19. Inheritance
  20. Abstract Keyword
  21. Polymorphism
  22. Collection
  23. Coroutines
  24. Generics
  25. Regex
  26. Interoperability with Java
  27. Kotlin for Android
  28. Extras
  29. Interoperability with JavaScript
  30. Glossary
  31. Important Question About the Author
  Swati Saxena is expert in Java programming and coding as she is MCA, OCJP ( Oracle Certified Java Professional ) and ADST, having in-depth knowledge of subject and very vast experience in developing and training. Her knowledge and teaching is always praised by her mentor as well as students. She has written "C programming and coding Question Bank with solution', "Java-A Complete Practical Solution" for BPB Publications. The alumnus of her, are well placed in many reputed organisations all over India.
  

CHAPTER 1

OOP in Brief

OOP stands for object-oriented programming, refers to a programming methodology based on objects, instead of just functions and procedures.

Advantage of OOPs Over Procedure-oriented Programming Language

• OOPs makes development and maintenance easier, where as, in procedure-oriented programming language, it is not easy to manage the code if it grows as the project size grows.
• OOPs provides data hiding, whereas, in procedure-oriented programming language, a global data can be accessed from anywhere.
• OOPs provides the ability to simulate real-world events much more effectively.
• We can provide the solution of real world problem if we are using object-oriented programming languages.

What is an object?

An object is an entity which has a well-defined structure and behavior. Everything in world is an object if it has some identity, state, behavior, and responsibility.

Characteristics of an object:

• State
• Behavior
• Identity
• Responsibility

Features of OOP

The features of OOP are as follows:

• Abstraction
• Encapsulation
• Inheritance
• Polymorphism

Abstraction

Abstraction is the process of identifying the key aspects of an entity and ignoring the rest. Data abstraction is a programming (and design) technique that relies on the separation of interface and implementation.

Advantages of data abstraction are:

• It makes the application secure by making data private and avoiding the user-level error that may corrupt the data
• It avoids code duplication

For example, a man has all the following properties but according to the need he is asked for the following information:

Social Survey	Health Care	Employment
Name	Name	Name
Age	Age	Age
Marital status	Address	Address
Religion	Blood group	Qualification
Income group	Weight	Department
Address	Previous record	Job responsibility
…….	……..	……..

Encapsulation

Encapsulation is a mechanism used to hide the data, internal structure, and implementation details of an object.

Data encapsulation led to the important OOP concept of data hiding. Data encapsulation is a mechanism of bundling the data, and the functions that use them and data abstraction is a mechanism of exposing only the interfaces and hiding the implementation details from the user.

C++ supports the properties of encapsulation and data hiding through the creation of user-defined types, called classes.

Advantages of encapsulation:

• Encapsulation is useful in hiding the data of a class from an illegal direct access
• Encapsulation helps us in binding the data and the member functions of a class
• Encapsulation also helps us to make a flexible code which is easy to change and maintain

The main advantage of encapsulation is to protect the data from outside by giving access control. Encapsulation is the complement of abstraction.

Inheritance

Inheritance is the process by which one object can acquire the properties of another object.

When creating a class, instead of writing completely new data members and member functions, the programmer can designate that the new class should inherit the members of an existing class. This existing class is called the base/parent class, and the new class is referred to as the derived/child class.

Inheritance implements the “is a” relationship. For example, car is a vehicle.

In C++, you ca...

Table of contents

• Cover
• Kotlin at a Glance
• Copyright
• Dedication
• Preface
• Table of Contents
• Chapter 1: OOP in Brief
• Chapter 2: An Introduction to Java
• Chapter 3 An Introduction to Kotlin
• Chapter 4: Kotlin Architecture
• Chapter 5: Kotlin Token
• Chapter 6: Kotlin Input
• Chapter 7: Kotlin Operator
• Chapter 8: String Operations
• Chapter 9:Conditional Statements
• Chapter 10: Jumping Statement
• Chapter 11: Looping / Control Flow / Iteration
• Chapter 12: Kotlin Array
• Chapter 13: Null Safety
• Chapter 14: Kotlin Function
• Chapter 15: Function Scope
• Chapter 16: Kotlin Lambda Functions and Exception Handling
• Chapter 17: Kotlin OOPs
• Chapter 18: Constructor
• Chapter 19: Inheritance
• Chapter 20: Abstract Keyword
• Chapter 21: Polymorphism
• Chapter 22: Collection
• Chapter 23: Coroutines
• Chapter 24: Generics
• Chapter 25: Regex
• Chapter 26: Interoperability with Java
• Chapter 27: Kotlin for Android
• Chapter 28: Extras
• Chapter 29: Interoperability with JavaScript
• Glossary
• Important Question