Internet-programming_PIbd-2.../Library/node_modules/lodash/findKey.js

45 lines
1.3 KiB
JavaScript

var baseFindKey = require('./_baseFindKey'),
baseForOwn = require('./_baseForOwn'),
baseIteratee = require('./_baseIteratee');
/**
* This method is like `_.find` except that it returns the key of the first
* element `predicate` returns truthy for instead of the element itself.
*
* @static
* @memberOf _
* @since 1.1.0
* @category Object
* @param {Object} object The object to inspect.
* @param {Function} [predicate=_.identity] The function invoked per iteration.
* @returns {string|undefined} Returns the key of the matched element,
* else `undefined`.
* @example
*
* var users = {
* 'barney': { 'age': 36, 'active': true },
* 'fred': { 'age': 40, 'active': false },
* 'pebbles': { 'age': 1, 'active': true }
* };
*
* _.findKey(users, function(o) { return o.age < 40; });
* // => 'barney' (iteration order is not guaranteed)
*
* // The `_.matches` iteratee shorthand.
* _.findKey(users, { 'age': 1, 'active': true });
* // => 'pebbles'
*
* // The `_.matchesProperty` iteratee shorthand.
* _.findKey(users, ['active', false]);
* // => 'fred'
*
* // The `_.property` iteratee shorthand.
* _.findKey(users, 'active');
* // => 'barney'
*/
function findKey(object, predicate) {
return baseFindKey(object, baseIteratee(predicate, 3), baseForOwn);
}
module.exports = findKey;