JavaScript Map clear() Method

JavaScript Map.clear() method is used for the removal of all the elements from a map and making it empty. It removes all the [key, value] from the map. No arguments are required to be sent as parameters to the Map.clear() method and it returns an undefined return value.

Syntax:

mapObj.clear()

Parameters:

• No parameters are required in the Map.clear() method.

Return Value:

• Map.clear() method has an undefined return type.

Examples of the above method are provided below.

Example 1: In this example, a map object "myMap" has been created with a single [key, value] pair and the Map.clear() method is used to remove the [key, value] pair from "myMap". myMap.size() is used to check the number of [key, value] pairs belonging to the map object.

// creating a map object let myMap = new Map(); // Adding [key, value] pair to the map myMap.set(0, 'geeksforgeeks'); // displaying the number of // [key, value] pairs the map has console.log(myMap.size); // removing the [key, value] pairs of // the map using Map.clear() method myMap.clear(); // displaying the number of // [key, value] pairs the map has console.log(myMap.size); 

Output:

1
0

Example 2: In this example, a map object "myMap" has been created with a three [key, value] pairs and the Map.clear() method is used to remove all the [key, value] pairs from "myMap". myMap.size() is used to check the number of [key, value] pairs belonging to the map object.

// creating a map object let myMap = new Map(); // Adding [key, value] pair to the map myMap.set(0, 'geeksforgeeks'); myMap.set(1, 'is an online portal'); myMap.set(2, 'for geeks'); // displaying the number of // [key, value] pairs the map has console.log(myMap.size); // removing the [key, value] pairs // of the map using Map.clear() method myMap.clear(); // displaying the number of // [key, value] pairs the map has console.log(myMap.size); 

OUTPUT :

3
0

Applications:

• Map.clear() Method is used to remove all the [key, value] pairs of a map.

Exceptions:

• If the variable is not of the Map type then the Map.entries() operation throws a TypeError.

Supported Browsers:

• Chrome 38
• Edge 12
• Firefox 19
• Opera 25
• Safari 8