Kotlin allows us to assign default values to constructor parameters. The compiler automatically assigns default values if the object is created without passing the relevant values to the parameters:

class Person(val name: String, var age: Int = 0, var height : Double = 0.0 )

fun main(args: Array<String>) {

    val jon = Person("Jon")
    println("name ${jon.name}, age ${jon.age}, height ${jon.height}")

    val abid = Person("Abid", 40)
    println("name ${abid.name}, age ${abid.age}, height ${abid.height}")

    val igor = Person("Igor", 35, 6.0)
    println("name ${igor.name}, age ${igor.age}, height ${igor.height}")
}

Take a look at the following output. The default parameter is a really powerful option provided by Kotlin that helps us to write clean and concise code:

If we compare the power of default parameters with the primary and secondary constructors, we notice that a single line of a default parameter can achieve much more than the other approaches, in which we need to write hundreds of lines of code.