Best Kotlin Programming Guides to Buy in October 2025
Kotlin in Action, Second Edition
Head First Kotlin: A Brain-Friendly Guide
Android Programming with Kotlin for Beginners: Build Android apps starting from zero programming experience with the new Kotlin programming language
Head First Android Development: A Learner's Guide to Building Android Apps with Kotlin
Programming Android with Kotlin: Achieving Structured Concurrency with Coroutines
Kotlin from Scratch: A Project-Based Introduction for the Intrepid Programmer
Kotlin In-Depth: A Guide to a Multipurpose Programming Language for Server-Side, Front-End, Android, and Multiplatform Mobile (English Edition)
Kotlin: An Illustrated Guide
Functional Programming in Kotlin
To call an abstract method from a class parameter in Kotlin, you first need to define an interface or an abstract class that contains the abstract method. Then, you can create a class that implements the interface or extends the abstract class and provides an implementation for the abstract method. Finally, you can pass an instance of the class as a parameter to a function or method and call the abstract method through the interface or abstract class reference. This allows for polymorphic behavior and enables calling the abstract method on any subclass instances passed in as the parameter.
What is polymorphism in Kotlin?
Polymorphism in Kotlin is the ability of a function or method to behave differently based on the object it is called on. It is achieved through inheritance and method overloading or overriding. In Kotlin, polymorphism allows different classes to be treated as instances of a common superclass, allowing them to be used interchangeably in code. This helps in achieving code reusability and flexibility in object-oriented programming.
How to override a method in Kotlin?
To override a method in Kotlin, follow these steps:
- Create a subclass that inherits from the parent class where the method you want to override is defined.
open class Parent { open fun doSomething() { println("Parent class method") } }
class Child : Parent() {
}
- Use the override keyword before the method declaration in the subclass.
override fun doSomething() { println("Child class method") }
- Call the method on an instance of the subclass to see the overridden behavior.
fun main() { val child = Child() child.doSomething() // This will print "Child class method" }
By following these steps, you can successfully override a method in Kotlin.
How to instantiate a class in Kotlin?
To instantiate a class in Kotlin, you can simply use the new keyword followed by the class name and parentheses. Here is an example:
class MyClass { fun myFunction() { println("Hello, World!") } }
fun main() { val myObject = MyClass() myObject.myFunction() }
In this example, we define a class MyClass with a function myFunction. We then create an instance of MyClass called myObject using the new keyword. Finally, we call the myFunction method on the myObject instance to print "Hello, World!" to the console.
What is the syntax for invoking a method in Kotlin?
The syntax for invoking a method in Kotlin is as follows:
methodName(argument1, argument2, ...)
Where methodName is the name of the method being called and argument1, argument2, etc. are the arguments passed to the method.