I have this map: private val listOfFeeds : Map<String, String> If I try to access an element with val s = listOfFeeds[key] The return type of "s" is String? And not String. I guess that's because the compiler can't assume it'll get a value for that key. Right? And if so, how can I work around the problem? Is !! the only solution here?

Do a null check:

val s = listOfFeeds[key]
if (s == null) {
  // code for null
} else {
  // code for non-null
}

Alternatively you can use

map.getOrDefault(key, defaultValue)

. Or, if you are really sure that it's not null you can use

!!

or

checkNotNull(map[key])

?:

is also possible

the

[]

indexing operator is just calling

get

which return a Nullable because the key might not exists you can use a fallback values with

?:

or throw in that case i like to use

?.let { doSomethingWith(it)}

personally andyou could also just use

!!

to null assert