Constructor

Constructor :-

• init Block  //code automatically run
• Primary Constructor
• Secondary Constructor  // have more than one secondary constructor

Primary Constructor :-

eg-1

//main function

fun main(args: Array<String>)

{

    val add = Add(5, 6)

    println("The Sum of numbers 5 and 6 is: ${add.c}")

}

//primary constructor

class Add constructor(a: Int,b:Int) //a and b can't be access from main

{

    var c = a+b;

}







eg-2




fun main(args: Array<String>) {

    val emp = employee(18018, "Sagnik")

}

class employee(emp_id : Int , emp_name: String) {

    val id: Int

    var name: String

  

    // initializer block

    init {

        id = emp_id

        name = emp_name

  

        println("Employee id is: $id")

        println("Employee name: $name")

    }

}




output:-

Employee id is: 18018 Employee name: Sagnik

Secondary Constructor :-

Prefix with Constructor

Allow initialization of variables 

Allow to provide some logic to the class as well

eg-1

fun main(args: Array<String>) {

    employee(18018, "Sagnik")

    employee(11011,"Praveen",600000.5)

}

class employee {

  

      constructor (emp_id : Int, emp_name: String ) {

          var id: Int = emp_id

          var name: String = emp_name

          print("Employee id is: $id, ")

          println("Employee name: $name")

          println()

      }

  

       constructor (emp_id : Int, emp_name: String ,emp_salary : Double) {

           var id: Int = emp_id

           var name: String = emp_name

           var salary : Double = emp_salary

           print("Employee id is: $id, ")

           print("Employee name: $name, ")

           println("Employee name: $salary")

       }

}







output:-

Employee id is: 18018, Employee name: Sagnik Employee id is: 11011, Employee name: Praveen, Employee name: 600000.5