C# Tutorial for Beginners 8 : Error handling (Try Catch Finally)

Summary

In this C# tutorial, the focus is on error handling using try-catch-finally blocks. The video demonstrates how to manage user input, particularly when expecting numbers, and how to handle exceptions like format and overflow errors. It shows how to display appropriate error messages, ensuring the program doesn't crash unexpectedly. Additionally, the finally block is explained as a tool for cleaning up resources such as file and database connections. This tutorial provides a clear understanding of implementing try-catch-finally for robust error handling in C# applications.

Takeaways

• 😀 Error handling in C# can be done using try-catch-finally blocks.
• 😀 The try block contains the code that may throw an exception.
• 😀 The catch block is used to handle exceptions, providing feedback to the user.
• 😀 You can specify the type of exception to handle, such as FormatException or OverflowException.
• 😀 Using specific exception types in the catch block allows for more precise error handling.
• 😀 In case of an unhandled error, you can add a generic catch block to handle unknown errors.
• 😀 The finally block always executes, regardless of whether an exception occurs or not.
• 😀 The finally block is useful for cleaning up resources, like closing file or database connections.
• 😀 Using try-catch-finally improves user experience by preventing ugly error messages.
• 😀 Proper exception handling allows for more robust and user-friendly applications.
• 😀 The next topics in the tutorial will cover if-statements and switch statements for conditional logic.

Q & A

What is the focus of this tutorial video?

The focus of this video is on error handling in C# using try-catch-finally blocks, specifically how to manage exceptions that can occur when taking user input, such as format and overflow exceptions.

What kind of error does the script handle when a user enters 'q' instead of a number?

The script handles a format exception when a user enters a non-numeric input like 'q'. The error message displayed is 'Format exception: Please enter a valid number'.

What is the purpose of the try block in the provided script?

The try block is used to execute code that might throw exceptions. In this case, it attempts to parse a string input into an integer, which can fail if the input is not a valid number.

What happens when the user enters a number that is too large for an integer?

When the user enters a number too large for an integer, an overflow exception is thrown, and the error message displayed is 'Overflow exception: Number was either too small or too big for an integer.'

What is the catch block used for in this script?

The catch block is used to handle specific exceptions that occur in the try block. In this script, it handles format exceptions and overflow exceptions, displaying appropriate error messages to the user.

What is the role of the finally block in error handling?

The finally block always executes, regardless of whether an exception occurred or not. It's typically used to clean up resources, such as closing files or database connections, ensuring they are properly released.

How does the script handle unknown exceptions?

If an unknown exception occurs, the script catches it with a generic exception handler, displaying a message like 'Unknown error has occurred' and suggesting that the user contact support for further assistance.

Why is it important to specify the type of exception in a catch block?

Specifying the type of exception, such as 'FormatException' or 'OverflowException', allows for more precise error handling. It enables the program to give the user a more informative and relevant error message specific to the problem.

What is the benefit of having a 'finally' block in a program?

The benefit of a 'finally' block is that it ensures certain code always runs, such as closing open files or database connections, preventing memory leaks or other resource management issues, regardless of whether an exception occurred.

What will the script display after a successful number input?

After a successful number input, the script will display the squared value of the number and the message 'This line always executes' before ending the program.