Best way to handle such scenario where “smart cast is imposible”

Question

I wonder what is the best way to handle such scenario

class Person(var name:String? = null, var age:Int? = null){
    fun test(){
        if(name != null &am         


        

Answer 1

For the cast to be possible you have to make a local copy of the value somehow. In Kotlin this is best done explicitly:

val name = name
val age = age
if(name != null && age != null){
    doSth(name, age)
}

The let function hides this behind an abstraction layer, which is not the best IMHO.