# 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 ```typescript 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 ```typescript 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 ```