Advantage of Exception/Error Handling with When Exception/Error can occur?

Advantage of Exception/Error Handling:

·         Error-handling codes are separated from the normal program flow to increase the readability and maintainability.

·         This location of the exception/error is known exactly as entire stack trace is available to the user. This is very helpful in debugging.

·         Programmer gets a chance to recover from the error/abnormal condition.

·         With java, it is not must to test if an exception/error condition happens. Adding more error/exception simply requires adding more catch clauses, but the original program flow need not be touched.

When Exception/Error can occur?

There are many cases where abnormal condition occurs during program execution, such as:

·         The class file you want to load may be missing or in the wrong format.

·         Integer division by zero

·         Array index is not the valid range (i.e. from 0 to length -1)

·         The file you are trying to open may not exits.

·         The file string, which you want to convert to a number, is having invalid characters so that it cannot be converted to a number.

·         You want to create an object but no more memory is available

In java for each and every exception there is a class.

The super class of all exceptions is Throwable.

Exception cl                               ass contains details of the exception which occurs under the normal circumstances.

Error class contains those exceptions which do not occur under the normal circumstances e.g. stack overflow. These exception are not handled under normal situation

Pre-Defined Classes of the Exception class:

Class                                                                                                    Description

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1. ArithmeticException                                               This class exception occurs when we divide the number by zero.

2. ArrayIndexOutofBoundsException                       This class exception occurs when we refer to an index outside the bounds or its size (0 to size-1).

3.ClassNotFoundException                                        This class exception occurs when we either create an object or reference of class , which we have not defined or which neither occurs in any package.

4. StringIndexOutofBoundsException                      This class exception occurs when we refer to an index outside the bounds  in case of a string.

5. NegativeArraySizeException                                 This class exception occurs when we specify a negative value as an array size

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