complying with ES6 and some JS standards

sample.js

@@ -1,12 +1,12 @@
 /*
  * Copyright 2013. Amazon Web Services, Inc. All Rights Reserved.
- * 
+ *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -15,22 +15,22 @@
 **/
 
 // Load the SDK and UUID
-var AWS = require('aws-sdk');
-var uuid = require('node-uuid');
+const AWS = require('aws-sdk');
+const uuid = require('node-uuid');
 
 // Create an S3 client
-var s3 = new AWS.S3();
+const s3 = new AWS.S3();
 
 // Create a bucket and upload something into it
-var bucketName = 'node-sdk-sample-' + uuid.v4();
-var keyName = 'hello_world.txt';
+const bucketName = `node-sdk-sample-${uuid.v4()}`;
+const keyName = 'hello_world.txt';
 
-s3.createBucket({Bucket: bucketName}, function() {
-  var params = {Bucket: bucketName, Key: keyName, Body: 'Hello World!'};
-  s3.putObject(params, function(err, data) {
+s3.createBucket({Bucket: bucketName}, () => {
+  const params = {Bucket: bucketName, Key: keyName, Body: 'Hello World!'};
+  s3.putObject(params, (err, data) => {
     if (err)
       console.log(err)
     else
-      console.log("Successfully uploaded data to " + bucketName + "/" + keyName);
+      console.log('Successfully uploaded data to ' , bucketName , '/' , keyName);
   });
 });