Why can I not use variable? [Kotlin] - selenium

Question

I am a Java developer who just switched to Kotlin and I haven't completely unterstood it yet.
I cant understand why I cant use my obj in the other methods in my following code..?
I use kotlin on IntelliJ in combination with selneium(which shouldnt really make a difference, should it?)
I tried putting it out of the init method but that didnt work either...
Thanks in advance.
import org.openqa.selenium.By
import org.openqa.selenium.chrome.ChromeDriver
class MapsDriver()
{
init {
var obj : ChromeDriver = ChromeDriver()
}
fun convertToGmURL(string : String) : String{
var string_trimmed : String = ""
string.forEach {
if(it == ' '){
string_trimmed += "+"
}
else{
string_trimmed += it
}
}
return string_trimmed
}
fun searchMaps(search : String){
val searchConverted : String = convertToGmURL(search)
obj.get("https://www.google.com/maps/search/?api=1&query=$searchConverted")
}
fun getXpath(Xpath : String) : String{
loop#while(true) {
try {
var result = obj.findElementByXPath(Xpath)
return result.text
}
catch (NoSuchElementException : Exception){
continue#loop
}
}
}
fun getResultName(resultNumber : Int) : String{
val convertedIndex : Int = (resultNumber * 2) + 1
var result : String = getXpath("//*[#id=\"pane\"]/div/div[1]/div/div/div[4]/div[1]/div[$convertedIndex]/div[1]/div[1]/div[1]/div[2]/h3/span")
return result
}
fun getAllResults(){
Thread.sleep(1_000)
val amountIndexes = getXpath("//*[#id=\"pane\"]/div/div[1]/div/div/div[4]/div[2]/div/div[1]/span/span[2]")
val amountIndexesInt : Int = amountIndexes.toInt()
val resultsName : Array<String> = Array(amountIndexesInt){getResultName(it)}
resultsName.forEach { println(it) }
}
}
fun main(){
System.setProperty("webdriver.chrome.driver", "/home/josef/Java/cdriver/chromedriver")
val md : MapsDriver = MapsDriver()
md.searchMaps("Autohaus Muenchen")
md.getAllResults()
}

Answer 1

The issue is that obj is a variable local to the init method, so it's equivalent to the following Java code:
class MapsDriver {
public MapsDriver() {
ChromeDriver obj = new ChromeDriver();
// you can't use obj anywhere else as it's local to the constructor
}
}
If you want obj to be an instance variable, then you should do something like:
class MapsDriver {
private val obj = ChromeDriver() // instance variable, no need for init block in this case
...
}