38 lines
911 B
JavaScript
38 lines
911 B
JavaScript
var isNumber = require('./isNumber');
|
|
|
|
/**
|
|
* Checks if `value` is `NaN`.
|
|
*
|
|
* **Note:** This method is based on
|
|
* [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as
|
|
* global [`isNaN`](https://mdn.io/isNaN) which returns `true` for
|
|
* `undefined` and other non-number values.
|
|
*
|
|
* @static
|
|
* @memberOf _
|
|
* @since 0.1.0
|
|
* @category Lang
|
|
* @param {*} value The value to check.
|
|
* @returns {boolean} Returns `true` if `value` is `NaN`, else `false`.
|
|
* @example
|
|
*
|
|
* _.isNaN(NaN);
|
|
* // => true
|
|
*
|
|
* _.isNaN(new Number(NaN));
|
|
* // => true
|
|
*
|
|
* isNaN(undefined);
|
|
* // => true
|
|
*
|
|
* _.isNaN(undefined);
|
|
* // => false
|
|
*/
|
|
function isNaN(value) {
|
|
// An `NaN` primitive is the only value that is not equal to itself.
|
|
// Perform the `toStringTag` check first to avoid errors with some
|
|
// ActiveX objects in IE.
|
|
return isNumber(value) && value != +value;
|
|
}
|
|
|
|
module.exports = isNaN;
|