Map

`Map.prototype.clear`

Removes all key-value pairs from the Map object

Syntax

JavaScript

map.clear()

Return Value

undefined

Examples

Basic Usage

const map = new Map([['a', 1], ['b', 2], ['c', 3]]);
console.log(map.size); // 3
map.clear();
console.log(map.size); // 0

Practical Example

const cache = new Map<string, unknown>();
function resetCache() {
  cache.clear();
  console.log('Cache cleared');
}

Advanced Usage

const map = new Map([['x', 1]]);
map.clear();
console.log(map.has('x')); // false

Understanding Map.prototype.clear

The Map.prototype.clear method in JavaScript removes all key-value pairs from the Map object. It belongs to the Map object and is one of the most widely used methods for working with map values in modern JavaScript and TypeScript applications.

The method signature is map.clear(). When called, it returns undefined. Understanding when and how to use clear() helps you write more expressive, readable code.

Common use cases for Map.prototype.clear include data transformation, input validation, API response processing, and building reusable utility functions. It works well alongside related methods like map-delete, map-set, set-clear, enabling you to chain operations together for complex data manipulation pipelines.

Browser support for Map.prototype.clear is excellent across all modern browsers including Chrome, Firefox, Safari, and Edge. It is also fully supported in Node.js and Deno. For older environments, transpilation with Babel or a polyfill may be needed.