Questions about Kotlin

Question

In this kotlin code, when we write map{it.toInt()} what is "map" and what is "it"?
why is it also valid to write map{String :: toInt} ?
ALSO, here we are able to assign values using userinput to 3 variables together using val (x, y, z) what is this feature called? is it available in java as well?

https://code.sololearn.com/cTGNdP6IDs5d/?ref=app

Answer 1

When we use function types we may also provide names for parameters, this further improves clarity of code:

val sin: (angleInRadians: Double) -> Double = Math::sin

Math::sin // method reference
this is equivalent to { x -> Math.sin(x) }

Function references in Kotlin: use functions as lambdas everywhere
https://antonioleiva.com/function-references-kotlin/

Reference to a function
::happyNewYear // function reference
happyNewYear( x ) // function call

https://try.kotlinlang.org/#/Examples/Callable%20references/Reference%20to%20a%20function/Reference%20to%20a%20function.kt

Answer 2

Asirap Practice time! 😄💪😁👍

Function references in Kotlin:
use functions as lambdas everywhere
https://code.sololearn.com/cEVm894IJ93R/?ref=app

Answer 3

A beginner's guide to Kotlin
https://blog.bugsnag.com/introduction-to-kotlin/

Answer 4

https://code.sololearn.com/c02Vi9dPdVk4/?ref=app
https://code.sololearn.com/c2ho07cgv097/?ref=app

Answer 5

Asirap 👍I'm glad,
I knew you would understand, because I'm learning this way too! 🤓

It's not a problem, you can freely use everything you need, the codes are written to make it easier for us.💪

I have more useful codes, but when I find them, I'll let you know.

Have a nice Coding my friend! ;)🍻

Answer 6

Asirap 😉 Gordon 💪
You are welcome! 😊
I will explain 👍

🙌Happy 🍾New year ...🎆 🍻

Answer 7

https://code.sololearn.com/c1xfdiI2b892/?ref=app
https://code.sololearn.com/chCQ5mP79z9C/?ref=app

Answer 8

Basic tutorial about lambda, also by Danijel:
https://code.sololearn.com/WNtO9vg0wvxE/?ref=app

Best resource for learning Kotlin: Tutorial published by Danijel 👍👍👏👏🌄🌅🎆🎇🎆🎉🎊🎊
A catalog is here:
https://code.sololearn.com/WKFF4vOCr3mi/?ref=app

Answer 9

Assigning multiple values in one statement like you showed is called destructuring. It's not possible to do it in Java, unfortunately.

Answer 10

thank you Danijel Ivanović . I did not know about lambdas in programming before, it's hard to wrap my head around it. What's the -> thing?
Also can you please recommend any resources that would give me a very basic idea about lambdas and all?

Answer 11

thank you! can you please explain the difference between map{it.toInt()}
and map{String::toInt} and how they do the same thing?
Danijel Ivanović Gordon

Answer 12

Danijel Ivanović I've understood what -> is finally! thank you for making the codes. i've made a web code where I've included links to some of your codes as reference hope that's okay. Also can you kindly also explain my question in the comments about String::toInt please?

Answer 13

thank you so much again! this is going to help me learn kotlin better and faster! Danijel Ivanović

Answer 14

Danijel Ivanović saved to my kotlin list
https://code.sololearn.com/WISXv8tPWjPL/?ref=app

Answer 15

LunarCoffee thank you! no one else answered that part of my question :D