Dart Map keys
Syntax & Examples

Syntax of Map.keys

The syntax of Map.keys property is:

 Iterable<K> keys

This keys property of Map the keys of this Map object.

Return Type

Map.keys returns value of type Iterable<K>.


✐ Examples

1 Get keys from a map of ages

In this example,

  1. We create a map named ages containing the ages of individuals.
  2. We use the keys property of the map ages to get an iterable containing all the keys.
  3. We print the keys to standard output.

Dart Program

void main() {
  Map<String, int> ages = {'Alice': 30, 'Bob': 25, 'Charlie': 35};
  Iterable<String> mapKeys = ages.keys;
  print('Keys in the map: $mapKeys');
}

Output

Keys in the map: (Alice, Bob, Charlie)

2 Get keys from a map of numbers

In this example,

  1. We create a map named numbers containing numeric mappings.
  2. We use the keys property of the map numbers to get an iterable containing all the keys.
  3. We print the keys to standard output.

Dart Program

void main() {
  Map<int, String> numbers = {1: 'one', 2: 'two', 3: 'three'};
  Iterable<int> mapKeys = numbers.keys;
  print('Keys in the map: $mapKeys');
}

Output

Keys in the map: (1, 2, 3)

3 Get keys from a map of flags

In this example,

  1. We create a map named flags containing boolean flags.
  2. We use the keys property of the map flags to get an iterable containing all the keys.
  3. We print the keys to standard output.

Dart Program

void main() {
  Map<String, bool> flags = {'enabled': true, 'disabled': false};
  Iterable<String> mapKeys = flags.keys;
  print('Keys in the map: $mapKeys');
}

Output

Keys in the map: (enabled, disabled)

Summary

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