How to Clear All Key-Value Pairs from a Map in Dart - Step by Step Examples

How to Clear All Key-Value Pairs from a Map in Dart ?

Answer

To clear all key-value pairs from a map in Dart, you can use the clear method. This method removes all elements from the map, leaving it empty.

✐ Examples

1 Clearing All Key-Value Pairs Using clear Method

We can clear all key-value pairs from a map in Dart using the clear method, which removes all elements from the map.

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 clear method to remove all key-value pairs from the map.
We print the length of the map using the length property to verify that the map is empty.

Dart Program

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

    // Clear all key-value pairs using clear method
    myMap.clear();

    // Print the length of the map
    print('Length of the map after clearing: ${myMap.length}');
}

Output

Length of the map after clearing: 0

2 Clearing an Already Empty Map

We can use the clear method on an already empty map in Dart, and it will still leave the map empty.

For example,

We start by declaring and initializing an empty map named myMap. In this example, the map has string keys and integer values.
We use the clear method to remove all key-value pairs from the map, even though it is already empty.
We print the length of the map using the length property to verify that the map is still empty.

Dart Program

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

    // Clear the map using clear method
    myMap.clear();

    // Print the length of the map
    print('Length of the map after clearing: ${myMap.length}');
}

Output

Length of the map after clearing: 0

3 Clearing a Map After Inserting Elements

We can insert key-value pairs into a map and then clear all key-value pairs using the clear method.

For example,

We start by declaring and initializing a map named myMap and inserting some key-value pairs into it. In this example, the map has string keys and integer values.
We use the clear method to remove all key-value pairs from the map.
We print the length of the map using the length property to verify that the map is empty.

Dart Program

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

    // Clear all key-value pairs using clear method
    myMap.clear();

    // Print the length of the map
    print('Length of the map after clearing: ${myMap.length}');
}

Output

Length of the map after clearing: 0

Summary

In this tutorial, we learned How to Clear All Key-Value Pairs from a Map in Dart language with well detailed examples.

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How to Clear All Key-Value Pairs from a Map in Dart - Step by Step Examples