Fun adder(a: Int, b: Int) : Int{ or fun adder(a: Int, b: Int) = a + b

Kotlin lang

1. 
   Function
   

Has return type

fun adder(a: Int, b: Int) :Int{ or fun adder(a: Int, b: Int) = a + b

return a + b}

Doesn’t have return type

Fun printer(s: String) print s

2. 
   Stringdan ma’lumot o’qib olish ${ } bilan
   

3. 
   O’zgaruvchi. 1ta o’zgarmas qiymat qabul qisa val, o’zgaruvchan qiymat qabul qisa var
   

Qiymat berish.

val age: Int = 5

var count: Int = 0

4. 
   Classda getter, setter metodlari automatic yaratilgan bo’ladi. Override qilish uchun
   

set(value){ get{

field = value*2 return field }

} field - bu age maydonda turgan qiymat

5. 
   Constructor
   

Kotlinda 2 xil constructor bor. Primary va Secondary

Primary constructor faqat 1dona bo’ladi, initialize blockdan ham oldin ishga tushadi

Class Car(var a: Int, b: Int){

}

Car lambo = Car( 5 )

Bu yerda a – maydon, b – parameter

Secondary constructor xohlagancha yaratish mumkin.

Constructor(a: Int, b: Int){

}

agar primary constructor bo’lsa, :this bilan primary chaqirilishi shart.

constructor(a: Int, b: Int) : this (10, 20) {

}

6. 
   Vorislik. class by default final bo’ladi. classni ochish uchun open ishlatildi
   

open class A{

}

Class B : A(){

}

7. 
   Istalgan son maydon bo’lishi mumkin
   

5.toStrng