kotlin map add value if doesn't equal

Question

I have a val valuesMap = mutableMapOf<String, String>() I want to add new value if keys of map doesn't equalsIgnoreCase new value.

if(!valuesMap.keys.equalsIgnoreKeys("value")) {
 valuesMap.put("value", null)
}

Something like this, but in kotlin we have only equals method for keys.

Answer 1

This iterates through the key set and compares lower-cased keys to the given term (new key).

val map: MutableMap<String, String?> = mutableMapOf()
val term = "value"
val contains = map.keys.any { key ->
    key.toLowerCase() == term.toLowerCase()
}
if (!contains) {
    map.put(term, null)
}

Answer 2

Why not use a specific map for your use case:

val caseInsensitive = TreeMap<String, String>(String.CASE_INSENSITIVE_ORDER)

The following constructor is used here:

public TreeMap(Comparator comparator)

Constructs a new, empty tree map, ordered according to the given comparator. All keys inserted into the map must be mutually comparable by the given comparator: comparator.compare(k1, k2) must not throw a ClassCastException for any keys k1 and k2 in the map. If the user attempts to put a key into the map that violates this constraint, the put(Object key, Object value) call will throw a ClassCastException.

Parameters: comparator - the comparator that will be used to order this map. If null, the natural ordering of the keys will be used.