CODEWITHSUNDEEP
androidkotlin
Павел Малиновский
Павел Малиновский

Reputation: 19

lateinit property has not been initialized I can not find a way to Initialize it

I have lateinit property in my Kotlin activity, this is simplified version of that:

class CreateNewListOfQuestions : AppCompatActivity() {
    lateinit var questionAnswerListOfObjects: ArrayList<QuestionAnswerObject>
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_create_new_list_of_questions)

        save.setOnClickListener {
            questionAnswerListOfObjects.add(0, QuestionAnswerObject("question", "answer", 1))
        }
    }
}

The main problem is that when I generate mobile app and press “Save” button app stops working. Logcat shows this error: “lateinit property questionAnswerListOfObjects has not been initialized”

I was trying many ways to initialize it but these ways did not help to me. How should I properly initialize it? I am plining to add to ArrayList many objects of this class:

class QuestionAnswerObject(var question: String, var answer: String, var probability: Int=100) {}

Upvotes: 1

Views: 10658

Answers (1)

Andrey Danilov
Andrey Danilov

Reputation: 6602

It depends what you want.

For example if everything you need is using ArrayList<QuestionAnswerObject> you dont need lateinit at all:

var questionAnswerListOfObjects = ArrayList<QuestionAnswerObject>()

would be enough

If you want to get from Bundle or from something else - you must initialize it before using.

Basically lateinit keyword is used only to say "hey, compiler, I have a variable, it is not initialized yet, but I promise it will be initialized before I use it, so please mark it as not nullable field".

So if you really want to use lateinit, just init that property earlier, for example add after setContentView

questionAnswerListOfObjects = ArrayList<QuestionAnswerObject>()

Upvotes: 7

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