Confused about Kotlin's companion object definition

Question

When i reach the companion object section in the ebook "Kotlin in action" it said that:

"if you need to write a function that can be called without having a class instance but needs access to the internals of a class, you can write it as a member of an object declaration inside that class"

As my understanding this means a function of the companion object can access the method and properties of the class that contain it. But when i try to implement this i can't access the members of the class from its companion object'function:

class Normal() {

var name: String = "hallo"


companion object {
    fun printName() {
        println(name) // ERROR!!! unresolved reference name
    }
}}

Did i misunderstood about this concept?

Answer 1

Method inside companion are kind of static by default(compared to Java & also this is how you achieve static kind of things in Kotlin) and you can not access normal variable from static method.

Same is happening here.

Edit:-

The definition in book is confusing, A companion object is not part of an instance of a class. You can't access members from a companion object, just like in Java you can't access members from a static method. But in case of utility classes where you just need to perform some operation you can call Static method which create a new instance of class and the perform some functions.

For example you can check answer by @user8320224, I am also quoting his code here,

class Normal {
private var name: String = "hallo"
private fun printName() {
    println(name)
}

companion object {
    fun factoryNormal(): Normal {
        val normal = Normal()
        normal.printName()
        normal.name = "new name"
        normal.printName()
        return normal
    }
}
}