Some cosmetic issues.

src/array.js

Index: src/array.js
diff --git a/src/array.js b/src/array.js
index e2aa4ad116724922d55dc7b9ffa129b967f23596..95d4ada1646e41d415b43e468717638af1119124 100644
--- a/src/array.js
+++ b/src/array.js
@@ -1107,7 +1107,7 @@ function SetupArray() {
     if (specialFunctions.hasOwnProperty(name)) {
       f = specialFunctions[name];
     }
-    if (arguments.length == 3) {
+    if (!IS_UNDEFINED(len)) {
       %FunctionSetLength(f, len);
     }
     return f;