I'm trying to find a clean way to build a full name out of nullable components. I'm sure you can do ...

# codereview

[Ellen Spertus]

I'm trying to find a clean way to build a full name out of nullable components. I'm sure you can do better than I did:

class Person (val personalName: String?, val middleInitial: String?, val familyName: String?) {
    override fun toString(): String {
        val nameParts = mutableListOf<String>()
        if (personalName != null) nameParts.add(personalName)
        if (middleInitial != null) nameParts.add(middleInitial)
        if (familyName != null) nameParts.add(familyName)
        return nameParts.joinToString(separator = " ")
    }
}

[ephemient]

listOfNotNull() is a standard library function

listOfNotNull(personalName, middleInitial, familyName).joinToString(" ")

[ephemient]

(but of course you wouldn't actually do this, right? https://www.kalzumeus.com/2010/06/17/falsehoods-programmers-believe-about-names/)

[Ellen Spertus]

I'm trying to motivate null for an introductory programming class that uses Kotlin. I was planning to mention that great article you link to and examples of people who don't have various components.

[Ellen Spertus]

I'm not sure that name properties are compelling, since you could argue for using the empty string.

The students haven't seen lists yet, so I can't use them in the example.

[Ellen Spertus]

@ephemient If you don't think name components should be joined together, what do you advocate (independent of whether null is used)?

[ephemient]

for names specifically? the only reliable way to determine a user's full name without cultural assumptions is to ask them

[ephemient]

for an exercise, sure… although without pointers I don't think there is really any good motivation for why references can be null

[Ellen Spertus]

Yeah, I'm reaching the same conclusion. I have introduced classes so could use a family tree that tops out at Adam and Eve.

[Ellen Spertus]

I ended up creating a Friend class and showing why you can't do:

val calvin = Friend("Calvin", bestFriend = hobbes)
val hobbes = Friend("Hobbes", bestFriend = calvin)