addAll method Null safety

void addAll(
  1. Map<K, V> other
)
override

Adds all key/value pairs of other to this map.

If a key of other is already in this map, its value is overwritten.

The operation is equivalent to doing this[key] = value for each key and associated value in other. It iterates over other, which must therefore not change during the iteration.

final planets = <int, String>{1: 'Mercury', 2: 'Earth'};
planets.addAll({5: 'Jupiter', 6: 'Saturn'});
print(planets); // {1: Mercury, 2: Earth, 5: Jupiter, 6: Saturn}

Implementation

void addAll(Map<K, V> other) {
  for (K key in other.keys) {
    this[key] = other[key] as V;
  }
}