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