UNPKG

817 BJavaScriptView Raw
1/** Used as the `TypeError` message for "Functions" methods. */
2var FUNC_ERROR_TEXT = 'Expected a function';
3
4/**
5 * Creates a function that negates the result of the predicate `func`. The
6 * `func` predicate is invoked with the `this` binding and arguments of the
7 * created function.
8 *
9 * @static
10 * @memberOf _
11 * @since 3.0.0
12 * @category Function
13 * @param {Function} predicate The predicate to negate.
14 * @returns {Function} Returns the new function.
15 * @example
16 *
17 * function isEven(n) {
18 * return n % 2 == 0;
19 * }
20 *
21 * _.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
22 * // => [1, 3, 5]
23 */
24function negate(predicate) {
25 if (typeof predicate != 'function') {
26 throw new TypeError(FUNC_ERROR_TEXT);
27 }
28 return function() {
29 return !predicate.apply(this, arguments);
30 };
31}
32
33export default negate;