Singleton Pattern in Java Script using Lazy Instantiation

Singleton pattern provide a way group of code and logical unit can access through a single instance. In JavaScript it can be used for namespacing, which reduce number of global variable in your class. It can also use encapsulate browser different through a technique known as branching.

Singleton patten example through java script

var StringUtil = window.StringUtil || {}
         
           StringUtil.DataParser = (function(){
             
               var uniqueInstance;
             
               function constructor(){
                 
                   var whiteSpaceReges = /\s+/;
                 
                   function stropWhiteSpace(str){
                       return str.replace(whiteSpaceReges,'');
                   }
                 
                   function stringSplit(str, delimiter){
                       return str.split(delimiter);
                   }
                 
                   this.stringToArray = function(str, delimiter, stripWS){
                       if(stripWS){
                           str = stropWhiteSpace(str);
                       }
                       var outputArray = stringSplit(str, delimiter);
                       return outputArray;
                   }
               }
             
               return {
                   getInstance: function(){
                       if(!uniqueInstance){
                           uniqueInstance = new constructor();
                       }
                       return uniqueInstance;
                   }
               }
           })();
         

Run the code:
var testStr = 'Hello , World, Test ';
var output = StringUtil.DataParser.getInstance().stringToArray(testStr,',',false);
output.length -> 3