whereKey method

Map<K, V> whereKey(
  1. bool f(
    1. K key
    )
)

Allows us to find an entry based on key

Example:

people.whereKey((key) => key.length < 5);
// {John: 20, Mary: 21}

const Map<String, int> people = {'John': 20, 'Mary': 21, 'Peter':20};

Implementation

Map<K, V> whereKey(bool Function(K key) f) =>
    {...where((key, value) => f(key))};