Updated reduce instructions

SunJieMing · SunJieMing · commit 0ed83ef86cea · 2017-10-02T16:49:22.000-07:00
diff --git a/src/arrays.js b/src/arrays.js
@@ -18,7 +18,8 @@ const map = (elements, cb) => {
 
 const reduce = (elements, cb, startingValue) => {
   // Combine all elements into a single value going from left to right.
-  // Elements will be passed one by one into `cb`.
+  // Elements will be passed one by one into `cb` along with the `startingValue`.
+  // `startingValue` should be the first argument passed to `cb` and the array element should be the second argument.
   // `startingValue` is the starting value.  If `startingValue` is undefined then make `elements[0]` the initial value.
 };
 
