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/**
* Lo-Dash 2.4.1 (Custom Build) <http://lodash.com/>
* Build: `lodash modularize exports="node" -o ./compat/`
* Copyright 2012-2013 The Dojo Foundation <http://dojofoundation.org/>
* Based on Underscore.js 1.5.2 <http://underscorejs.org/LICENSE>
* Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
* Available under MIT license <http://lodash.com/license>
*/
var createCallback = require('../functions/createCallback'),
forOwn = require('./forOwn');
/**
* This method is like `_.findIndex` except that it returns the key of the
* first element that passes the callback check, instead of the element itself.
*
* If a property name is provided for `callback` the created "_.pluck" style
* callback will return the property value of the given element.
*
* If an object is provided for `callback` the created "_.where" style callback
* will return `true` for elements that have the properties of the given object,
* else `false`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to search.
* @param {Function|Object|string} [callback=identity] The function called per
* iteration. If a property name or object is provided it will be used to
* create a "_.pluck" or "_.where" style callback, respectively.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {string|undefined} Returns the key of the found element, else `undefined`.
* @example
*
* var characters = {
* 'barney': { 'age': 36, 'blocked': false },
* 'fred': { 'age': 40, 'blocked': true },
* 'pebbles': { 'age': 1, 'blocked': false }
* };
*
* _.findKey(characters, function(chr) {
* return chr.age < 40;
* });
* // => 'barney' (property order is not guaranteed across environments)
*
* // using "_.where" callback shorthand
* _.findKey(characters, { 'age': 1 });
* // => 'pebbles'
*
* // using "_.pluck" callback shorthand
* _.findKey(characters, 'blocked');
* // => 'fred'
*/
function findKey(object, callback, thisArg) {
var result;
callback = createCallback(callback, thisArg, 3);
forOwn(object, function(value, key, object) {
if (callback(value, key, object)) {
result = key;
return false;
}
});
return result;
}
module.exports = findKey;