How to Convert a Map to an Array of Keys in Dart

How to Convert a Map to an Array of Keys in Dart ?

Answer

To convert a map to an array of keys in Dart, you can use the keys property. This property returns an iterable of all the keys in the map, which can be converted to a list.

✐ Examples

1 Converting a Map to an Array of Keys Using keys Property

We can convert a map to an array of keys in Dart using the keys property, which provides an iterable of all keys in the map. We can then convert this iterable to a list.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use the keys property to get an iterable of the keys in the map.
We convert the iterable to a list using the toList method.
We store the list of keys in a variable named keysList.
We print the list of keys to the console using the print function to verify the conversion.

Dart Program

void main() {
    // Declare and initialize a map
    Map<String, int> myMap = {
        'one': 1,
        'two': 2,
        'three': 3
    };

    // Convert map to an array of keys
    List<String> keysList = myMap.keys.toList();

    // Print the keys
    print('Keys: $keysList');
}

Output

Keys: [one, two, three]

2 Converting an Empty Map to an Array of Keys

We can also convert an empty map to an array of keys in Dart using the keys property, which returns an empty list when the map is empty.

For example,

We start by declaring an empty map named emptyMap with string keys and integer values.
We use the keys property to get an iterable of the keys in the empty map.
We convert the iterable to a list using the toList method.
We store the list of keys in a variable named emptyKeysList.
We print the list of keys to the console using the print function to verify that the list is empty.

Dart Program

void main() {
    // Declare an empty map
    Map<String, int> emptyMap = {};

    // Convert empty map to an array of keys
    List<String> emptyKeysList = emptyMap.keys.toList();

    // Print the keys
    print('Keys: $emptyKeysList');
}

Output

Keys: []

3 Converting a Map to an Array of Keys After Adding Elements

We can convert a map to an array of keys in Dart after adding elements using the keys property, which provides an updated iterable of all keys in the map.

For example,

We start by declaring an empty map named dynamicMap with string keys and integer values.
We add some key-value pairs to the map using the map's index notation.
We use the keys property to get an iterable of the keys in the map after adding elements.
We convert the iterable to a list using the toList method.
We store the list of keys in a variable named dynamicKeysList.
We print the list of keys to the console using the print function to verify the updated list of keys.

Dart Program

void main() {
    // Declare an empty map
    Map<String, int> dynamicMap = {};

    // Add elements to the map
    dynamicMap['one'] = 1;
    dynamicMap['two'] = 2;
    dynamicMap['three'] = 3;

    // Convert map to an array of keys after adding elements
    List<String> dynamicKeysList = dynamicMap.keys.toList();

    // Print the keys
    print('Keys: $dynamicKeysList');
}

Output

Keys: [one, two, three]

Summary

In this tutorial, we learned How to Convert a Map to an Array of Keys in Dart language with well detailed examples.

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