Question { iFlex, 6912 }

what is the need of the Ajax?

Answer

in ajax we can send the request to server and get responce
from the server without submit the page(clicking button and
send the form ).

Question { 10113 }

what is the purpose of class "Object" which is base class
for all classes?

Answer

The Object class sits at the top of the class hierarchy
tree in the Java development environment. Every class in
the Java system is a descendent (direct or indirect) of the
Object class. The Object class defines the basic state and
behavior that all objects must have, such as the ability to
compare oneself to another object, to convert to a string,
to wait on a condition variable, to notify other objects
that a condition variable has changed, and to return the
object's class.

Question { 13585 }

How to convert String into primitive datatype.

Answer

using parseInt() method for example

//String to primitive types
int iVal = Integer.parseInt(str);
long lVal = Long.parseLong(str);
float fVal = Float.parseFloat(str);
double dVal = Double.parseDouble(str);

Question { Ericsson, 8860 }

Which of these methods belong to Thread & Object class?
join, yield, sleep, wait, notify

Answer

methods inherited from java.lang.Object
*clone
*equals
*finalize
*getClass
*hashCode
*notify
*notifyAll
*wait

and this three methods join, yield, sleep belongs to Threads
class

Question { Ericsson, 12230 }

What are the two ways you can synchronize a block of code?

Answer

There are two ways to syanchronize access to an object

1st one is using synchronized keyword for example

Synchronized type methodname(arg-list)
{
//synchrinized method body
}

2nd way s using synchronized block

synchronized(object)
{
//synchronized statement

}