addAll method

@override void addAll(Map other)

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

@override
void addAll(Map other) {
  if (other is JsBackedMap) {
    // Object.assign is more efficient than iterating through and setting properties in Dart.
    addAllFromJs(other.jsObject);
  } else {
    super.addAll(other);
  }
}