Update 0535-encode-and-decode-tinyurl.js

Looking at the code I noticed that the toString function there was pointless considering the fact that js type coersion already converts the number to the string during concatenation. Also I also noticed the else block only returned true or false rather than the string as the question requested, so I added what I think is a fitting solution to that.

javascript/0535-encode-and-decode-tinyurl.js

@@ -1,22 +1,18 @@
 // problem link https://leetcode.com/problems/encode-and-decode-tinyurl
 // time complexity O(1)
 
-
 const encodeMap = new Map();
 const decodeMap = new Map();
 const base = 'http://tinyurl.com/';
 
 var encode = function(longUrl) {
     let shortUrl = ''
     if(!encodeMap.has(longUrl)) {
-            shortUrl = (base + encodeMap.size + 1).toString();
+            shortUrl = base + encodeMap.size + 1
             encodeMap.set(longUrl, shortUrl);
             decodeMap.set(shortUrl, longUrl);
-        } else {
-            return encodeMap.has(longUrl);
-        }
-
-        return shortUrl;
+        } 
+        return shortUrl || encodeMap.get(longUrl);
 };
 
 var decode = function(shortUrl) {