Aim : To write a program that demonstrates how various exceptions are caught with catch.

Algorithm: Step 1: Class Design  Define a class named ExceptionA which inherits from the built-in class Exception.  Define ExceptionA class with appropriate onstructors and methods if needed.  Define a class named ExceptionB which inherits from ExceptionA.  Define ExceptionB class with appropriate constructors and methods if needed. Step 2: Creating main()  Declare variables and objects as needed.  Use try blocks to encapsulate code sections where exceptions may occur. Step 3: Within each try block:  Throw exceptions of types ExceptionA, ExceptionB and IOException.  For NullPointerException, initialize a null string and calculate the length of the string. [Trying to access the length method on null string results in an Exception] Step 4: Use catch blocks to catch exceptions of type Exception.  Handle each caught exception appropriately within the catch blocks.