Why the modifier on property is the same as Getter and Setter but not Field after Java being translated into Kotlin?

Question

Official Ref says the default Visibility Modifier is public.

But from koan data classes it can be inferred that it is private.

Is it a contradiction? What is the default Visibility Modifier of property in kotlin?

---------The above is the initial question---------------

I didn't mix property and field up. But I did have confusion on how property is accessed.

To resolve my confusion, I actually should have asked the new question in edited title.

Self-answered below.

jrtapsell jrtapsell · Accepted Answer · 2018-03-13T10:12:29

What it the default Visibility Modifier for properties in kotlin?

It is public, as the docs say

Why are the fields not private

In this example the fields are immutable, so there are no setters defined automatically. The data class automatically has getters, and uses them, but it simplifies reading the code by not requiring them to be manually called.

Worked example

This code:

object X {
    data class Example(val a: String, val b: String)
    @JvmStatic
    fun main(args: Array<String>) {
        val e = Example("a", "b")
        println(e.a)
        println(e.b)
    }
}

The main method of this compiles to this (with checks and metadata removed):

public static final void main(String[] args) {
    X.Example e = new X.Example("a", "b");
    String var2 = e.getA();
    System.out.println(e.getA());
    var2 = e.getB();
    System.out.println(var2);
}

(Decompiled using IntelliJ IDEA)

Why the modifier on property is the same as Getter and Setter but not Field after Java being translated into Kotlin?

3 Answers

What it the default Visibility Modifier for properties in kotlin?

Why are the fields not private

Worked example