Exception Handling Basics Quiz

Exception Handling

• An exception is an event that occurs during the execution of a program that disrupts the normal flow of instructions.
• Exception handling is the process used to change the normal flow of code execution if a specified exception occurs.

Types of Exceptions

• Checked exceptions: occur during compilation
• Unchecked exceptions: occur during execution (also known as runtime exceptions)

Exception Descriptions

• ClassNotFoundException: the class is not found
• IllegalAccessException: access to a class is denied
• InstantiationException: attempt to create an object of an abstract class or an interface
• NoSuchMethodException: a requested method does not exist
• ArithmeticException: arithmetic error, such as an integer divided by 0
• ArrayIndexOutOfBoundsException: accessing an invalid index of the array
• ArrayStoreException: assigning a value to an array index that does not match the expected data type
• InputMismatchException: entering a value that does not match the expected data type
• NullPointerException: invalid use of a null reference
• NumberFormatException: invalid conversion of a string to a numeric format
• StringIndexOutOfBoundsException: accessing an invalid index (character) of a string

try, catch, and finally Blocks

• A try block is a block of code that might throw an exception that can be handled by a matching catch block.
• A catch block is a segment of code that can handle an exception that might be thrown by the try block that precedes it.
• The getMessage() method can be used to determine Java's message about the exception.
• Only one try block is accepted in a program, but there can be multiple catch blocks.
• The finally block contains statements which are executed whether or not an exception is thrown.
• There can only be one finally block after a try-catch structure, but it is not required.

User-Defined Exceptions

• A user-defined exception is created by extending the Exception class.
• A throw statement sends an exception out of a block or a method so it can be handled elsewhere.

Test your knowledge on basic exception handling concepts. Learn about different types of exceptions such as ClassNotFoundException and IllegalAccessException, and how to handle them in your programs.