Java Questions

Q:

What is polymorphism?

Answer

It is the ability of an object to behave differently on different situations for the same message.

Report Error

View answer Workspace Report Error Discuss

Subject: Java

0 2009
Q:

How to get last modified date of a file?

Answer

long lastModified();


we can give this return value to a date object and we can get data to be displayed.

Report Error

View answer Workspace Report Error Discuss

Subject: Java

0 2008
Q:

Why interface data is static?

Answer

Interface data is static data why bcoz interface supports multiple inheritance.


if inteface data is non-static then there is chance for replication of the data (bcoz of replication of data ambiguity problem occurs )

Report Error

View answer Workspace Report Error Discuss

Subject: Java

0 2006
Q:

What are the steps required to execute a query in JDBC?

Answer

First we need to create an instance of a JDBC driver or load JDBC drivers, then we need to register this driver with DriverManager class. Then we can open a connection. By using this connection , we can create a statement object and this object will help us to execute the query.

Report Error

View answer Workspace Report Error Discuss

Subject: Java

0 2004
Q:

What is Constructor?

Answer

Constructor is not a special method.


Constructor is block of code that is executed automatically whenever object of the class is created.

Report Error

View answer Workspace Report Error Discuss

Subject: Java

0 1997
Q:

What is the differnce among public, protected and package access data?

Answer

If we are not using packages and if we are not using inheritance then there is no difference among public, protected and package access data.

Report Error

View answer Workspace Report Error Discuss

Subject: Java

0 1990
Q:

What is anonymous class?

Answer

Anonymous class is class without name.


EX:


class A {


}


class Demo {


    A r = new A() {


        }; //anonymous class


}


 

Report Error

View answer Workspace Report Error Discuss

Subject: Java

0 1966
Q:

What is the difference between throw and throws clause?

Answer

A throw is used to throw an exception manually, where as throws is used in the case of checked exceptions, to tell the compiler that we haven't  handled the exception, so that the exception will be handled by the calling function.

Report Error

View answer Workspace Report Error Discuss

Subject: Java

0 1956