--- /dev/null
+var baseFlatten = require('./internal/baseFlatten'),
+ baseOrderBy = require('./internal/baseOrderBy'),
+ isIterateeCall = require('./internal/isIterateeCall'),
+ rest = require('./rest');
+
+/**
+ * Creates an array of elements, sorted in ascending order by the results of
+ * running each element in a collection through each iteratee. This method
+ * performs a stable sort, that is, it preserves the original sort order of
+ * equal elements. The iteratees are invoked with one argument: (value).
+ *
+ * @static
+ * @memberOf _
+ * @category Collection
+ * @param {Array|Object} collection The collection to iterate over.
+ * @param {...(Function|Function[]|Object|Object[]|string|string[])} [iteratees=[_.identity]]
+ * The iteratees to sort by, specified individually or in arrays.
+ * @returns {Array} Returns the new sorted array.
+ * @example
+ *
+ * var users = [
+ * { 'user': 'fred', 'age': 48 },
+ * { 'user': 'barney', 'age': 36 },
+ * { 'user': 'fred', 'age': 42 },
+ * { 'user': 'barney', 'age': 34 }
+ * ];
+ *
+ * _.sortBy(users, function(o) { return o.user; });
+ * // => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]]
+ *
+ * _.sortBy(users, ['user', 'age']);
+ * // => objects for [['barney', 34], ['barney', 36], ['fred', 42], ['fred', 48]]
+ *
+ * _.sortBy(users, 'user', function(o) {
+ * return Math.floor(o.age / 10);
+ * });
+ * // => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]]
+ */
+var sortBy = rest(function(collection, iteratees) {
+ if (collection == null) {
+ return [];
+ }
+ var length = iteratees.length;
+ if (length > 1 && isIterateeCall(collection, iteratees[0], iteratees[1])) {
+ iteratees = [];
+ } else if (length > 2 && isIterateeCall(iteratees[0], iteratees[1], iteratees[2])) {
+ iteratees.length = 1;
+ }
+ return baseOrderBy(collection, baseFlatten(iteratees), []);
+});
+
+module.exports = sortBy;