--- title: isNil tags: type,beginner --- Returns `true` if the specified value is `null` or `undefined`, `false` otherwise. - Use the strict equality operator to check if the value of `val` is equal to `null` or `undefined`. ```js const isNil = val => val === undefined || val === null; ``` ```js isNil(null); // true isNil(undefined); // true isNil(''); // false ```