Kotlin Tutorial
Kotlin Extension Function (Explained With Examples)
Table of Contents
- Introduction
- What is Extension Function in Kotlin?
- Use of Kotlin Extension
- Kotlin Extension Function Example
- How to Declare Extension Function in Kotlin?
- Kotlin Extension Function Visibility
- Override Kotlin Extension Function
- Extended Library Class Using Extension Function
- Resolution of Kotlin Extensions
- Defining Extension Function With Nullable Receiver
- Companion Object Extensions in Kotlin
- Advantages of Extension Functions in Kotlin:
- Disadvantages of Extension Functions in Kotlin
- Suitable scenarios for Using Extension Functions in Kotlin
- Kotlin Full Course Video for Beginners [FREE]
Kotlin Full Course Video for Beginners [FREE]
Kotlin Extension Function FAQs
To define an extension function, you use the fun keyword followed by the name of the function and the type you want to extend. The type you are extending is specified as the receiver type using dot notation.
No, you cannot override extension functions in subclasses. Extension functions are resolved statically at compile time based on the declared type of the object, not dynamically at runtime based on the actual type of the object.
Extension functions are resolved statically based on the declared type of the object. When you call an extension function on an object, the compiler determines which function to call at compile time based on the declared type of the variable or expression.
Yes, extension functions can be defined for nullable types, allowing you to work with nullable objects and perform null-checks within the extension function.
You can organize extension functions by placing them in appropriate packages or files based on their usage and visibility. Naming conventions and documentation can also help clarify their purpose.
No, extension functions are not part of the class they extend. They are separate functions defined outside of the class and are called as if they were member functions of the class, but they don't modify the class itself.
Yes, you can define extension functions for Java classes in Kotlin. However, there are some limitations, such as not being able to access private members of Java classes.
