JavaScript - Map.clear() Method

The Map.clear() method in JavaScript is used to remove all elements from a Map object. This method returns nothing as result (i.e. undefined) instead, it removes all the elements from the Map object.

Syntax

Following is the syntax of JavaScript Map.clear() method −

clear()

Parameters

This method does not accept any parameters.

Return value

This method returns nothing (i.e. undefined).

Examples

Example 1

In the following example, we are using the JavaScript Map.clear() method to remove all elements from this map −

<html>
<body>
   <script>
      let map = new Map();
      map.set('key1', 'value1');
      map.set('key2', 'value2');
      document.write(map.size, "<br>"); // Output: 2
      map.clear();
      document.write(map.size); // Output: 0
   </script>
</body>
</html>

As we can see in the output, it removed all the elements.

Example 2

In this example, we have initialized a Map with three key-value pairs using an array of arrays. Later, we used the clear() method to remove all the entries in it −

<!DOCTYPE html>
<html>
<body>
   <script>
      const myMap = new Map([
         ['apple', 5],
         ['banana', 8],
         ['orange', 3]
      ]);
      document.write(myMap.size, "<br>"); // Output: 3
      myMap.clear();
      document.write(myMap.size); // Output: 0
   </script>
</body>
</html>

As we can see in the output, the size of the Map after using the clear() method is 0.