Bump to v4.0.0.

size.js

@@ -0,0 +1,35 @@
+define(['./isArrayLike', './isString', './keys', './internal/stringSize'], function(isArrayLike, isString, keys, stringSize) {
+
+  /**
+   * Gets the size of `collection` by returning its length for array-like
+   * values or the number of own enumerable properties for objects.
+   *
+   * @static
+   * @memberOf _
+   * @category Collection
+   * @param {Array|Object} collection The collection to inspect.
+   * @returns {number} Returns the collection size.
+   * @example
+   *
+   * _.size([1, 2, 3]);
+   * // => 3
+   *
+   * _.size({ 'a': 1, 'b': 2 });
+   * // => 2
+   *
+   * _.size('pebbles');
+   * // => 7
+   */
+  function size(collection) {
+    if (collection == null) {
+      return 0;
+    }
+    if (isArrayLike(collection)) {
+      var result = collection.length;
+      return (result && isString(collection)) ? stringSize(collection) : result;
+    }
+    return keys(collection).length;
+  }
+
+  return size;
+});