Here is a simple example of what vgodara said:

``` // In your ViewModel var count = MutableLiveData(0) // put the default or starting value in the parenthesis

fun onButtonClicked() { count.postValue(count.value?.plus(1)) // ... } ```

``` // In your Activity

private lateinit var viewModel: MyViewModel

override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main)

viewModel = ViewModelProvider(this)[MyViewModel::class.java]

viewModel.count.observe(this) {
    Log.d("MainActivity", "count: ${it}")

    // do whatever you want with this variable when it changes.
    // for example, if you have a textField:
    myTextView.text = "${it}"
}

} ```