HCLTech Lead Engineer interview questions

2) What is Lamda Expression? is it possible to compare two dates using Lambda expressions? 3) What is difference between Abstract Class And Interface? 4) Why Abstract class is Partially Unimplemented ? 5) How to implement multiple inheritance in C#? 6)Difference between String And StringBuilder ? 7)Difference between Document.Ready() and Document.Window() ? 8) What is page error handling? 9)What is selectors? 10)What is Instance Context Modes? 11)How to Provide Security to Authorized Users? 12)In service hosting in IIS , How to test the service in Client System? 13)How handle Exceptions in Server? 14)How to test Wcf Service ? How to Pass the Object? 15)Where you implement the security for services in our application? 16)How to handle exception in current User Name, Password? 17)what is WCFService and WebService? 18)What is Transport level & Message Level Security?