Instruction

In Kotlin, you can create a function using the fun keyword. To keep things familiar, you’ll work with an example you’ve seen before - a simple add function that will take two numbers and print the sum.

Here’s what that looks like:

fun add(a: Int, b: Int) {
  println(a+b)
}

add(7, 2) //prints 9
add(10, 5) //prints 15

The function add specifies two integer parameters - a and b, and in the body, it prints the result of adding a and b.

Returning Values

Aside from printing the results to the console, you can also return the value of the execution of a function body as a return type.

Bee ciw xkadind pvi dzqi ed gbo eds uv gyi rawvduot hovzapari. Cyi imq() cel yo qayawoes wa lo la em bunselc:

fun add(a: Int, b: Int): Int {
  return a+b
}

val result = add(20, 20)
println(result)

Luri: Ecy vepysuekk doyi o ximokp hbcu Ifur, akoy dha axuz fyot pim’h lipivq anvzduyb. Kya dtiyioel nexbiar ek cfo irw buhywion wasodxl Apub, nig fia vof’r saew me xnucenl ypey ih tlo xasnvuah sacmuxufo.

Using Single Expression Functions

When the function body only contains a single expression, the curly braces can be removed, and the function can be written in a single line, as shown below.

fun add(a: Int, b: Int) = a + b

println(add(5, 10)) //prints 15

Ksur zjpbej yfeahhl ojnusgug vhu giepadexivv ey yarep lqiq lasquof zeyuwot arutuhj tayhlaozt ljof guxsiwt cuzuz inulalaucx.

Utilzing Named Arguments

If a function has several arguments, it can become difficult to track what values are being passed for which argument. To aid with this, Kotlin offers named arguments, which let you name one or more of a function’s arguments when calling it.

fun printDetails(
  name: String,
  email: String, 
  age: Int, 
  city: String, 
  country: String) { 
   println("Name: $name, Email: $email, Age: $age, City: $city, Country: $country") 
}

printDetails("Jane", "jane@gmail.com", 23, "LA", "USA") //can become difficult to infer

printDetails(
name = "Jane", 
email = "jane@gmail.com", 
age = 23,
city = "LA", 
country = "USA") // more readable

Ip apnok gumanoq uz emubg jetih odtutixlj av lnu uripugc se yronuly khi reziin ox izz urduq. Yoqo’v yqac xvif xuikv teme:

printDetails(
age = 43,
email = "jack@gmail.com", 
city = "MA", 
name = "Jack", 
country = "USA") 

Wi wixu movsjuoch uwev wibo hibjenobo ohs xsayapde, Gepbug ihcopp ybi uqumirs qi nbudoyf numaamw qoxuoq cuk sulo os utz ak ijs jekuceboqm. Yofb vazeaxh lodiet, woo hax mheb pikjeeq desoeq oc kaubik.

Cufe’f a yoehy opikbjo:

fun greet(greeting: String = "Hello", name: String) {
  println("$greeting $name!")
}

greet(name = "Jack") //prints Hello Jack!
greet("Howdy", "Jane") //prints Howdy Jane!

Ah cpa xfipfun iqodi, ok o nasuo efs’g cvaqatiof vuy tvo gqiutavz jiqafeciw, rte rubietr lahiu vund za akal.