This information is only valid when you use classic SharePoint experiences in SharePoint Online or in on-premises. Usage of classic SharePoint JavaScript Client Object Model is not supported with the ...

You're charged with engineering a new but important app that the company CEO wants all employees to add to their routines and it should be accessible from any device. The nature of the app would lend ...

SharePoint add-in model is considered as a legacy option for extending SharePoint user interface. Please see SharePoint Framework documentation and the SharePoint Framework samples for the future ...