1var isNumber = require('./isNumber');
2
3/**
4 * Checks if `value` is `NaN`.
5 *
6 * **Note:** This method is based on
7 * [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as
8 * global [`isNaN`](https://mdn.io/isNaN) which returns `true` for
9 * `undefined` and other non-number values.
10 *
11 * @static
12 * @memberOf _
13 * @since 0.1.0
14 * @category Lang
15 * @param {*} value The value to check.
16 * @returns {boolean} Returns `true` if `value` is `NaN`, else `false`.
17 * @example
18 *
19 * _.isNaN(NaN);
20 * // => true
21 *
22 * _.isNaN(new Number(NaN));
23 * // => true
24 *
25 * isNaN(undefined);
26 * // => true
27 *
28 * _.isNaN(undefined);
29 * // => false
30 */
31function isNaN(value) {
32  // An `NaN` primitive is the only value that is not equal to itself.
33  // Perform the `toStringTag` check first to avoid errors with some
34  // ActiveX objects in IE.
35  return isNumber(value) && value != +value;
36}
37
38module.exports = isNaN;
39