What is an exception handler? Explain how exceptions are handled in object-oriented languages.

An exception handler is a special block of code designed to catch and handle unexpected events or errors that occur during the execution of a program. It allows your program to gracefully recover from these events instead of crashing abruptly.

How Exceptions Are Handled in Object-Oriented Languages:

Object-oriented languages like Java, Python, C++, and others provide a structured way to handle exceptions using the following steps:

1. Exception Occurs: When an error happens, the program throws an exception object. This object contains information about the error, such as the type of error and where it occurred.
2. Exception Propagation: The exception object travels up the call stack until it reaches a matching try...catch block.
3. try...catch Block: The try block encloses the code that might throw an exception. The catch block immediately follows and specifies the type of exception it can handle.
4. Exception Handling: If the exception type matches the catch block, the code within the catch block is executed. This code can log the error, display a message to the user, or attempt to recover from the error.
5. finally Block (Optional): The finally block is executed regardless of whether an exception was caught or not. This is useful for cleaning up resources, such as closing files or releasing connections.

Example in Python:

try:
  # Code that might raise an exception
  result = 10 / 0 
except ZeroDivisionError:
  print("Cannot divide by zero!")
finally:
  print("This block always executes.")

In this example, dividing by zero will raise a ZeroDivisionError. The try...catch block catches this error and prints a message. The finally block executes regardless of the exception.

Benefits of Exception Handling:

• Robustness: Protects your program from crashing due to unexpected events.
• Code Clarity: Separates error handling logic from the main program flow.
• Maintainability: Makes it easier to debug and modify your code.

Practical Insights:

• Use specific exception types for different error scenarios.
• Avoid catching general Exception types unless absolutely necessary.
• Use finally blocks to ensure resources are released.