Java Questions

- The Set interface provides methods for accessing the elements of a finite mathematical set

- Sets do not allow duplicate elements

- Contains no methods other than those inherited from Collection

- It adds the restriction that duplicate elements are prohibited

- Two Set objects are equal if they contain the same elements

abstract method is a method declared with abstract modifier but  with out body.

Dynamic binding is orthogonal to dynamic linking. Binding refers to the linking of a procedure call to the code to be executed in response to the call. Dynamic binding It is associated with polymorphism and inheritance, it(also known as late binding) means that the code associated with a given procedure call is not known until the time of the call at run-time.

An abstract class is an incomplete class. An abstract class is defined with the keyword abstract . We cannot create an object of the abstract class because it is not complete. It sets a behavioral protocol for all its child classes.

The wait(), notify(), and notifyAll() methods are used to provide an efficient way for threads to wait for a shared resource. When a thread executes an object's wait() method, it enters the waiting state. It only enters the ready state after another thread invokes the object's notify() or notifyAll() methods..

File[] listFiles();

this method returns list of files stored in a directory.

Method contains name, parameters, return type and executable body. But block does not contains name, parameters, return type.It contains only executable body.

Methods are executed by method call statements. Blocks are executed automatically with class loading and with object creation.

To use an iterator to traverse through the contents of a collection, follow these steps:

- Obtain an iterator to the start of the collection by calling the collections iterator() method.

- Set up a loop that makes a call to hasNext(). Have the loop iterate as long as hasNext() returns true.

- Within the loop, obtain each element by calling next().