Classes and Objects

Class Basics

Create an object and read a property.

class A class defines a type of object with named properties.

Class Basics

name
ClassBasics.kt
Replay: real traced execution (multi-file project)
class Badge(val name: String)

fun main() {
    val name = "Kotlin"
    val badge = Badge(name)
    val label = badge.name

    println("name=$name")
    println("label=$label")
}

class Badge(val name: String)

fun main() {
    val name = "Ada"
    val badge = Badge(name)
    val label = badge.name

    println("name=$name")
    println("label=$label")
}

class Badge(val name: String)

fun main() {
    val name = "Lin"
    val badge = Badge(name)
    val label = badge.name

    println("name=$name")
    println("label=$label")
}

  1. name ← Kotlin, label ← Kotlin

    3fun main() {4    val name→ Kotlin = "Kotlin" //@name="Ada", "Lin"5    val badge = Badge(nameKotlin)6    val label→ Kotlin = badge.nameKotlin78    println("name=$nameKotlin")9    println("label=$labelKotlin")10}
    outputname=Kotlin
label=Kotlin

  1. name ← Ada, label ← Ada

    3fun main() {4    val name→ Ada = "Ada"5    val badge = Badge(nameAda)6    val label→ Ada = badge.nameAda78    println("name=$nameAda")9    println("label=$labelAda")10}
    outputname=Ada
label=Ada

  1. name ← Lin, label ← Lin

    3fun main() {4    val name→ Lin = "Lin"5    val badge = Badge(nameLin)6    val label→ Lin = badge.nameLin78    println("name=$nameLin")9    println("label=$labelLin")10}
    outputname=Lin
label=Lin