es-toolkit/docs/reference/predicate/isWeakMap.md

isWeakMap

Checks if the given value is a WeakMap.

This function tests whether the provided value is an instance of WeakMap. It returns true if the value is a WeakMap, and false otherwise.

This function can also serve as a type predicate in TypeScript, narrowing the type of the argument to WeakMap.

Signature

function isWeakMap(value: unknown): value is WeakMap<WeakKey, any>;

Parameters

value (unknown): The value to test if it is a WeakMap.

Returns

(value is WeakMap<WeakKey, any>): true if the value is a WeakMap, false otherwise.

Examples

const value1 = new WeakMap();
const value2 = new Map();
const value3 = new Set();

console.log(isWeakMap(value1)); // true
console.log(isWeakMap(value2)); // false
console.log(isWeakMap(value3)); // false