Hands-On Object-Oriented Programming with Kotlin

Secondary constructor

In Kotlin, like other programming languages, a class can have more than one constructor. A secondary constructor is prefixed with the constructor keyword and it is created inside the class.

Let's take a look at the following example. The Person class contains a primary constructor with the init block and the secondary constructor with the constructor keyword:

class Person(name: String, age: Int) {    var name : String    var age : Int    var height : Double    init {       this.name = name       this.age = age       this.height = 0.0      }    constructor(name: String, age: Int, height: Double) : this(name, age) {       this.height = height    } }

Creating a secondary constructor becomes necessary when you need to initialize a class in different ways. In this example, ...