I want to make a extension function in Kotlin, that converts the first letter of each word of the string to upper case the quick brown fox to The Quick Brown Fox I tried using the capitalize(...

I Kotlin if I have an interface like this: interface User { val name: String val email: String } I can write an extension function like this anywhere in the code: fun User.toUserDto(): UserDto {...

If we want to test an extension function on a type, we can create an instance of this type, call the function and check the returned value. But what about testing extension functions defined inside...

In Kotlin language, what does this syntax do and how does it work ? class ClassName1 { companion object { fun ClassName2.funName()="" } }

I want my extension function to have a couple of receivers. For example, I want function handle to be able to call methods of both CoroutineScope and Iterable instances: fun handle() { // I want t...

Kotlin version 1.2.50 I have been following some examples on this tutorial on youtube https://www.youtube.com/watch?v=gPH9XnvpoXE. And there are a few things that I have understood, but there is st...

How can I call a super's extension function? For example: open class Parent { open fun String.print() = println(this) } class Child : Parent() { override fun String.print() { print("child say...

Is it possible to access extension functions from Java code? I defined the extension function in a Kotlin file. package com.test.extensions import com.test.model.MyModel /** * */ public fun M...

I see some usages of Extension functions in Kotlin I don't personally think that makes sense, but it seems that there are some guidelines that "apparently" support it (a matter of interpr...

In Java you cannot extend a final class, but in Kotlin you can write extension method to such final classes. How did they make it work internally? I couldn't find any article that explained the inn...

I am very new to Kotlin. I want to be able to add a function to my abstract class, so when I define that function I will be able to invoke that on every child from that class(they inherit the abst...

I have a pretty short question about an extension function that would help clear some of my code. Basically I have some transformations on the hashCode of a class name and I want an extension funct...

I was reading about Kotlin and did not quite get the idea. From what I understood, an extension function adds behavior to instances of a class T without having to inherit from T. and what is receiv...

Suppose I have the following code that I want to make as a re-usable component: fun <T> MutableList<T>.swap(index1: Int, index2: Int) { val tmp = this[index1] // 'this' corresponds to...

We are currently switching our project to Kotlin, and ran across following question: We need a certain extension function only inside a given class. Thus, we have two possibilities: (1) Declaring ...

I read many Kotlin documents about these items. But I can't understand so clearly. What is the use of Kotlin let, also, takeIf and takeUnless in detail? I need an example of each item. Please don...

The only way I've found so far is to create an instance of the given class and then using the autocomplete to see all possible functions. Obviously, this way is cumbersome and takes too much time. ...

I want to create extension functions for classes that encapsulate simple Numbers. For example DoubleProperty. I encountered the problem, that I can't overload the + and the += operator at the same ...

Hey I want to make a class in kotlin that will hold all extension functions that I will use in a few places for example: class DateUtils { //in this case I use jodatime fun Long.toDateTime() : D...

Is it possible to create an extension function and call it as if it were static? For Example... fun System.sayByeAndExit() { println("Goodbye!") System.exit() } fun main(args: Array<String&...