Equivalent of getClass() for KClass

Java allows resolving a variable’s class with the getClass() function and Kotlin allows that with the .javaClass() function. The KClass type is Kotlin’s equivalent of Java’s java.lang.Class type.

Let’s see how to get a reference of the KClass similarly.

the getClass() Equivalent for KClass in Kotlin

The equivalent of something.getClass() for KClass is something::class. We can use this through the class reference syntax.

The class reference’s basic feature is to get a runtime reference to a KClass.

Syntax:

val v = Class_Name::class

Using ::class is possible only in Kotlin 1.1 and onwards. To do this in Kotlin 1.0, we need to get the Java Class and convert it to Kotlin Class instance with the help of the .kotlin property.

The syntax to get KClass instance in Kotlin 1.0 is:

Class_Name.javaClass.kotlin

We can also get the class object kotlin.reflect.KClass by using KClass::class. To get the current object’s class, we can use this::class.

The following code block shows how to resolve a variable’s class in Kotlin.

Example Code:

import kotlin.reflect.KClass
fun main(args : Array<String>) {

    // this will get us the reference of our KClass
    fun<A: Any> A.getClass(): KClass<A> {
        return javaClass.kotlin
    }

    val first_Variable = "This is a String"
    val second_Variable = 3

    // Since the first variable is String it gives java.lang.String
    println("Kotlin type: ${first_Variable.getClass()}")

    // Since the second variable is Integer it gives Int
    println("Kotlin type: ${second_Variable.getClass().simpleName}")

}

Output: