1.What is single inheritance.

ans:one class is inherited by only other one class

2.What is multiple inheritance.

ans:One class inheriting more than one class at atime.

3.Can java support multiple inheritance.

ans:No

4.what is interface?

ans:Interface has only method declarations but no defn

5.What is differenec between abstract class and interface?

ans:In abstract class some methods may contain definition,but in interface every method should be abstract.

6.How to you prove that abstrace class cannot instantiate directly?

ans:As they dont have constructor they cant be instantiated

7.What is differenece between string and stringbuffer?

ans:Strings are immutable where as string buffer can be modified.

8.What is immutable?

ans:Which cant be changed

9.What is main difference hashmap and hastable?

ans:Hash table is synchronised

10.What is main difference between array list and vector?

ans:Vector is synchronised

11.What is struts framework?

ans:It follows MVC architecture which is used for seperating view,controller,model

12.What is main difference between jsp and servlets.

ans:Jsp s are mainly used for dynamic presenatations where we can write code of design and actual content seperately.mainly coding becomes feasible

13.What is difference between procedure and functions?

ans:Fuctions can return value ,procedures cant return value

14.What is jdbc?

ans:Connecting to DB from java program requires JDBC

15.What are type of drivers?

type1,2,3,4

java suports multithreading