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Kotlin program | Example of constructor overloading

Kotlin | Constructor Overloading: Here, we are implementing a Kotlin program to demonstrate the example of constructor overloading.
Submitted by IncludeHelp, on June 03, 2020

Constructor Overloading

A Kotlin class has a primary constructor and one or more secondary constructors. When a class has more than one constructor, it will be known as constructor overloading.

Program for constructor overloading in Kotlin

package com.includehelp

//declare Class with Parameterized primary constructor
class ConstructorOverloading(len:Int){

    //Init block, executed when class is instantiated, 
    //before secondary constructor body execution
    init {
        println("Init Block  : $len")
    }

    //Secondary Constructor, 
    //delegate primary constructor with 'this' keyword
    constructor() : this(10) {
        println("Secondary Constructor No Parameter")
    }

    //Parameterized Secondary Constructor, 
    //delegate primary constructor with 'this' keyword
    constructor(name:String):this(name.length){
        println("Secondary Constructor with One Parameter  : $name")
    }

    //Parameterized Secondary Constructor with two parameter,
    //call same class non Parameterized secondary constructor 
    //using 'this()'
    constructor(a:Int, b:Int) : this() {
        println("Secondary Constructor With Two Parameter [$a, $b]")
    }
}


//Main Function, Entry Point of Program
fun main(args:Array<String>){

    //Create instance of class , with Primary Constructor
    ConstructorOverloading(100)

    //Create instance of class, 
    //with no argument secondary constructor
    ConstructorOverloading()

    //Create instance of class, 
    //with one argument secondary constructor
    ConstructorOverloading("India")

    //Create instance of class, 
    //with two argument secondary constructor
    ConstructorOverloading(10,20)
}

Output:

Init Block  : 100
Init Block  : 10
Secondary Constructor No Parameter
Init Block  : 5
Secondary Constructor with One Parameter  : India
Init Block  : 10
Secondary Constructor No Parameter
Secondary Constructor With Two Parameter [10, 20]