Bump to v3.4.0.

math/sum.js

@@ -0,0 +1,33 @@
+import isArray from '../lang/isArray';
+import toIterable from '../internal/toIterable';
+
+/**
+ * Gets the sum of the values in `collection`.
+ *
+ * @static
+ * @memberOf _
+ * @category Math
+ * @param {Array|Object|string} collection The collection to iterate over.
+ * @returns {number} Returns the sum.
+ * @example
+ *
+ * _.sum([4, 6, 2]);
+ * // => 12
+ *
+ * _.sum({ 'a': 4, 'b': 6, 'c': 2 });
+ * // => 12
+ */
+function sum(collection) {
+  if (!isArray(collection)) {
+    collection = toIterable(collection);
+  }
+  var length = collection.length,
+      result = 0;
+
+  while (length--) {
+    result += +collection[length] || 0;
+  }
+  return result;
+}
+
+export default sum;