If there are many list items you try retrieve with javascript object model,paging could be very useful. Today I came across a wonderful blog post series about javascript object model in SharePoint: The SharePoint javascript object model - Resources and Real World Examples posted by David Mann and published on Aptilon Blog. There is an example how to achieve paging with JSOM. The key is items.get_listItemCollectionPosition() and query.set_listItemCollectionPosition() I have refactored David’s example to avoid global variables and to put into a module. Here is it. If you have a Tasks list in your site with many items, just hit F12 to open the console and paste this and see the result:

Have you wondered what to use a singleton object  or a class with static methods. Well, here is an awesome comparision of these techniques. Static methods and classes are easy to use, but you can’t them as objects, implement interfaces and have constructors with parameters.