not null but undefined

Vemus · Vemus · commit 237d346053ba · 2016-10-22T10:49:28.000-07:00
diff --git a/code/solutions/04_1_the_sum_of_a_range.js b/code/solutions/04_1_the_sum_of_a_range.js
@@ -1,5 +1,5 @@
 function range(start, end, step) {
-  if (step == null) step = 1;
+  if (step == undefined) step = 1;
   var array = [];
 
   if (step > 0) {
