Optimize variables

Author: tshemsedinov

JavaScript/3-callback.js

@@ -1,25 +1,23 @@
 'use strict';
 
 const wrapFunction = fn => {
-  console.log('Wrap function: ' + fn.name);
+  console.log('Wrap function:', fn.name);
   return (...args) => {
-    console.log('Called wrapper for: ' + fn.name);
+    console.log('Called wrapper for:', fn.name);
     console.dir({ args });
     if (args.length > 0) {
-      let callback = args[args.length - 1];
+      const callback = args[args.length - 1];
       if (typeof callback === 'function') {
         args[args.length - 1] = (...args) => {
-          console.log('Callback: ' + fn.name);
+          console.log('Callback:', fn.name);
           callback(...args);
         };
-      } else {
-        callback = null;
       }
     }
-    console.log('Call: ' + fn.name);
+    console.log('Call:', fn.name);
     console.dir(args);
     const result = fn(...args);
-    console.log('Ended wrapper for: ' + fn.name);
+    console.log('Ended wrapper for:', fn.name);
     console.dir({ result });
     return result;
   };