An exception signifies the presence of an abnormal condition which requires special operable techniques. In programming terms, an exception is the anomalous code that breaks the normal flow of the code. Such exceptions require specialized programming constructs for its execution.
What is Exception Handling
In programming, exception handling is a process or method used for handling the abnormal statements in the code and executing them. It also enables to handle the flow control of the code/program. For handling the code, various handlers are used that process the exception and execute the code. For example, the Division of a non-zero value with zero will result into infinity always, and it is an exception. Thus, with the help of exception handling, it can be executed and handled.
In exception handling:
A throw statement is used to raise an exception. It means when an abnormal condition occurs, an exception is thrown using throw.
The thrown exception is handled by wrapping the code into the try…catch block. If an error is present, the catch block will execute, else only the try block statements will get executed.
Thus, in a programming language, there can be different types of errors which may disturb the proper execution of the program.
Types of Errors
While coding, there can be three types of errors in the code:
When a runtime error occurs, it creates and throws an Error object. Such an object can be used as a base for the user-defined exceptions too. An error object has two properties:
Although Error is a generic constructor, there are following standard built-in error types or error constructors beside it:
Exception Handling Statements
There are following statements that handle if any exception occurs:
These exception handling statements are discussed in the next section.