es-toolkit/docs/reference/predicate/isSymbol.md
D-Sketon 4d46377d9b
feat(isSymbol): implement isSymbol (#359)
* feat: implement isSymbol

* fix: make pure
2024-08-10 10:16:18 +09:00

758 B

isSymbol

Check whether a value is a symbol.

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

Signature

function isSymbol(value: unknown): value is symbol;

Parameters

  • value (unknown): The value to check.

Returns

(value is symbol): True if the value is a symbol, otherwise false.

Examples

import { isSymbol } from 'es-toolkit/predicate';

isSymbol(Symbol('a')); // true
isSymbol(Symbol.for('a')); // true
isSymbol(Symbol.iterator); // true

isSymbol(null); // false
isSymbol(undefined); // false
isSymbol('123'); // false
isSymbol(false); // false
isSymbol(123n); // false
isSymbol({}); // false
isSymbol([1, 2, 3]); // false