Android Development with Kotlin

Properties versus constructor parameters

The important thing to notice is the fact that if we remove the var/val keyword from the constructor property declaration, we'll end up with a constructor parameter declaration. This means that the property will be changed to a constructor parameter, so no accessors will be generated and we will not be able to access the property on the class instance:

    class Fruit(var weight:Double, fresh:Boolean) 
 
    val fruit = Fruit(12.0, true) 
    println(fruit.weight) 
    println(fruit.fresh) // error 

In the preceding example, we have an error because fresh is missing a val or var keyword, so it is a constructor parameter, not a class property such as weight. The following table summarizes the compiler accessor generation: ...