state_update_kotlin_view_model.kt

class MainViewModel: ViewModel() {

    private val _creditScore = MutableStateFlow(0)
    private val _age = MutableStateFlow(18)

    val isEligible = combine(_creditScore, _age) { creditScore, age ->
            creditScore > 400 && age > 18 && age < 70
    }

    fun creditScore(score: Int) {
        _creditScore.update {
            score
        }
    }

    fun age(age: Int) {
        _age.update {
            age
        }
    }
}