Property getter or setter expected in Kotlin

Question

I am learning Kotlin from official docs, I am trying to create a class to do arithmetic operations.

class Sum {

    var a: Int, b: Int;

    constructor(a: Int, b: Int) {
        this.a = a
        this.b = b
    }

    fun add(): Int {
        return a + b
    }
}

I have this class, now I want to create an object of this class like

val sum = Sum(1,2)
Log.d("Sum", sum.add())

I am getting this error in Sum class:

Property getter or setter expected

on b: int; within the line var a: Int, b: Int;

Answer 1

var a: Int, b: Int;

Kotlin doesn't allow to have multiple declarations in one line. You have to go for:

var a: Int
var b: Int

instead. The Kotlin folks simply found the C/java practice of "int a, b, .." to be something they wish to not support in Kotlin.

Answer 2

You are writing unnecessary code in your class.

Write short form for constructor if there is only one.

If there are properties in class, they can be defined in constructor by using val or var.

Use it like following:

class Sum (var a: Int,var b: Int){

    fun add(): Int {
        return a + b
    }
}

Do read Basic Syntax of Kotlin.