JavaScript Map clear()
Syntax & Examples

Map.clear() method

The clear() method of the Map object in JavaScript removes all key-value pairs from the Map object, effectively emptying it.

Syntax of Map.clear()

The syntax of Map.clear() method is:

clear()

This clear() method of Map removes all key-value pairs from the Map object.

Return Type

Map.clear() returns value of type undefined.


✐ Examples

1 Using clear() to empty a Map

In JavaScript, we can use the clear() method to remove all key-value pairs from a Map object.

For example,

  1. Create a new Map object map with initial key-value pairs.
  2. Use the clear() method to remove all key-value pairs from the map.
  3. Log the updated map to the console using console.log().

JavaScript Program

const map = new Map([['a', 1], ['b', 2], ['c', 3]]);
map.clear();
console.log(map);

Output

Map {}

2 Using clear() on an already empty Map

In JavaScript, using the clear() method on an already empty Map object will not cause any errors.

For example,

  1. Create a new, empty Map object map.
  2. Use the clear() method to clear the map.
  3. Log the updated map to the console using console.log().

JavaScript Program

const map = new Map();
map.clear();
console.log(map);

Output

Map {}

3 Using clear() after adding and removing elements from a Map

In JavaScript, we can use the clear() method after adding and removing elements from a Map object to empty it completely.

For example,

  1. Create a new Map object map with initial key-value pairs 'a' => 1 and 'b' => 2.
  2. Use the set() method to add the key 'c' with the value 3 to the map.
  3. Use the delete() method to remove the key 'a' from the map.
  4. Use the clear() method to remove all remaining key-value pairs from the map.
  5. Log the updated map to the console using console.log().

JavaScript Program

const map = new Map([['a', 1], ['b', 2]]);
map.set('c', 3);
map.delete('a');
map.clear();
console.log(map);

Output

Map {}

Summary

In this JavaScript tutorial, we learned about clear() method of Map: the syntax and few working examples with output and detailed explanation for each example.