How can I duplicate an object to another object, without changing the base object in Kotlin?

Question

this is my code:

var header1: Record? = null var header2: Record? = null  header2 = header1 header2.name = "new_name" 

but header1.name changes too!

Answer 1

You are just assigning the same object (same chunk of memory) to another variable. You need to somehow create a new instance and set all fields.

header2 = Record() header2.name = header1.name 

However in Kotlin, if the Record class was Data class, Kotlin would create a copy method for you.

data class Record(val name: String, ...) ... header2 = header1.copy() 

And copy method allows you to override the fields you need to override.

header2 = header1.copy(name = "new_name") 

Answer 2

If your Class is not a Data Class and your project has Gson and you want to copy the whole object ( probably edit after getting it ), Then if all those conditions are true then this is a solution. This is also a DeepCopy. ( For a data Class you can use the function copy()).

Then if you are using Gson in your project. Add the function copy():

class YourClass () {  // Your class other stuffs here    fun copy(): YourClass { //Get another instance of YourClass with the values like this!       val json = Gson().toJson(this)       return Gson().fromJson(json, YourClass::class.java)   } } 

If you want to install Gson then get the latest version here.