Thursday, 31 May 2018

Exception handling Recent changes with examples

Exception handling Recent changes with examples:


What is an exception?

Different handling is the process of addressing answering the event, during computation, of exclusions - anomalous or exceptional conditions requiring special control - often changing the normal flow of program execution. It is provided by specialized programming terminology constructs or computer hardware mechanisms.

Generally speakingOn the whole, an different is handled (resolved) by saving the current express of execution in a predefined place and moving over the execution to an unique subroutine known as very handler. If exceptions are continuable, the handler may later resume the performance at the original location using the saved information. For instance, a flying point divide by actually zero exception will typically, by default, allow the program to be resumed, while an out of memory condition might not be resolvable transparently.

Alternative strategies to exception handling in software are error looking atexamining, which maintains normal program flow with later direct checks for contingencies reported using special return principles or some auxiliary global variable such as C's errno or floating point status flags; or suggestions validation to preemptively filtering exceptional cases.

ENCAPSULATION

HOW YOU CAN HIDING THE INFORMATION BY USING ENCAPSULATION?

WHAT IS THE MAIN PURPOSE BY USING ENCAPSULATION?

     The main purpose of encapsulation method is desiging modular commucation protocols in computer networking.Which is logically separte functions in the network are abstrcted from their underlying structures by  high level objects information will be hide.

In the encapsulation it will be present in physical layer it is responsible for physical transmmision area networking and Internet Protocol(IP) it will also provides global addressiing of different computers;Transmmision Control Protocol(TCP) it is process selection. i.e,The port specifies the service such as aweb or tftp server.

Each encapsulation layer builds a Protocol Data Unit(PDU) we can add aheader (and sometimes trailer) it will contain the control information of PDU from the layer above.for example,in the internet protocol suite, the contents of a webpage are encapsulation with an HTTP header,then by a TCP header, and IP header, and finally, by aframe header and trailer. The frame is forwarded to destination node as a stream of bits,where it is de-encapsulation (or decapsulation) in to the respective PDUS and interpreted at each layer by the reciving node.