I use Kotlin to Programm Android Apps. For null-pointer safety one needs to check if all references are non-null. However if only one is null then we should inform the user that something went wrong.
It is important for me to program in a concise readable manner.
I am looking for a short and easy understandable solution.
The standard way would be:
if (b != null && a != null && c !=null ...) println ("everything ok.")
else println("Something went wrong")
Here are two concise expressions you can use.
This one valuates to true when all variables are non-null:
listOf(a, b, c).all { it != null }
This one evaluates to true when any variable is null:
listOf(a, b, c).any { it == null }
In context, this is how you can use the second one:
println(if (listOf(a, b).any { it == null })) "Something went wrong"
else "Everything ok.")