Dart Map addEntries()
Syntax & Examples

Syntax of Map.addEntries()

The syntax of Map.addEntries() method is:

 void addEntries(Iterable<MapEntry<K, V>> newEntries)

This addEntries() method of Map adds all key/value pairs of newEntries to this map.

Parameters

ParameterOptional/RequiredDescription
newEntriesrequiredan iterable of key/value pairs to add to the map

Return Type

Map.addEntries() returns value of type void.


✐ Examples

1 Add multiple entries to a map

In this example,

  1. We create a map map with initial key/value pairs.
  2. We create an iterable newEntries containing additional key/value pairs.
  3. We then use the addEntries() method to add all key/value pairs from newEntries to map.
  4. We print map after adding the entries to standard output.

Dart Program

void main() {
  var map = {'a': 1, 'b': 2};
  var newEntries = {'c': 3, 'd': 4}.entries;
  map.addEntries(newEntries);
  print(map);
}

Output

{a: 1, b: 2, c: 3, d: 4}

2 Add a single entry to a map

In this example,

  1. We create a map map with initial key/value pairs.
  2. We create an iterable newEntries containing a single key/value pair.
  3. We then use the addEntries() method to add the key/value pair from newEntries to map.
  4. We print map after adding the entry to standard output.

Dart Program

void main() {
  var map = {'x': 'apple', 'y': 'banana'};
  var newEntries = {'z': 'cherry'}.entries;
  map.addEntries(newEntries);
  print(map);
}

Output

{x: apple, y: banana, z: cherry}

3 Add a new ID to a map of names

In this example,

  1. We create a map map with initial key/value pairs representing IDs and names.
  2. We create an iterable newEntries containing a single key/value pair representing a new ID and name.
  3. We then use the addEntries() method to add the new ID and name to map.
  4. We print map after adding the entry to standard output.

Dart Program

void main() {
  var map = {'id1': 'John', 'id2': 'Doe'};
  var newEntries = {'id3': 'Jane'}.entries;
  map.addEntries(newEntries);
  print(map);
}

Output

{id1: John, id2: Doe, id3: Jane}

Summary

In this Dart tutorial, we learned about addEntries() method of Map: the syntax and few working examples with output and detailed explanation for each example.