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.

javascript

// 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.

javascript

// 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.

We have a complete list of Javascript Map methods, to check them please go through the Javascript Map Complete Reference article.

Supported Browsers: 

• Chrome 38 and above
• Edge 12 and above
• Firefox 19 and above
• Internet Explorer 11 and above
• Opera 25 and above
• Safari 8 and above