notContainsKey method
Whether this map does not contain the given key
.
Returns false if none of the keys in the map are equal to key
according to the equality used by the map.
final animalRatings = { "aardvark": 1, "baboon": 2 };
final notContainsAardvark = animalRatings.notContainsKey("aardvark"); // false
final notContainsCat = animalRatings.notContainsKey("cat"); // true
Implementation
bool notContainsKey(K key) => !containsKey(key);