data class uniinitialize by lateinit property-CodePudding

when i try to initialize data class it gives me error, kotlin.UninitializedPropertyAccessException: lateinit property article_ has not been initialized. How do i resolve this error and whats way to initialize data class.

model class

data class Article(
    val id: Int,
    val author: String,
    val content: String,
    val description: String?)

MainActivity

class TestActivity : AppCompatActivity() {
    lateinit var binding: ActivityTestBinding
    lateinit var article_: List<Article>

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = DataBindingUtil.setContentView(this,R.layout.activity_test)

val mainAdapter = MainAdapter(article_)
        binding.recView.apply {
            this.layoutManager = LinearLayoutManager(this@TestActivity)
            this.adapter = mainAdapter
        }
}
}

CodePudding user response：

ANSWER:

In onCreate() before this line val mainAdapter = MainAdapter(article_) just initialize the article_ by writing article_ = ArrayList() and the error will be gone.

Cause of Error

You are encountering this error because You need to initialize the lateinit variable article_ before using it and you are not doing it.

If you want to check that either the variable is initialized or not then use ::article_.isInitialized.

Feel free to ask if something is unclear.

CodePudding user response：

Change code like this binding = DataBindingUtil.setContentView(this,R.layout.activity_test) article_ = ArrayList()

CodePudding user response：

lateinit should only be used when you have a specific reason not to initialize the variable on construction. Here I can see no reason not to make it

var article_: List<Article> = listOf()

or perhaps

val article_: MutableList<Article> = mutableListOf()

and guarantee such error can't happen in the first place.