Lesson 5.4: Error Handling – Try…Catch, Throwing Errors

Web Development with HTML, CSS, JavaScript

Lesson 5.4: Error Handling – Try…Catch, Throwing Errors

In JavaScript, error handling is essential to ensure your code runs smoothly without crashing when something unexpected happens. This is done using try…catch blocks and throwing custom errors.

1. Why Error Handling?

Prevents program crashes due to runtime errors.
Provides meaningful messages to users or developers.
Helps in debugging and maintaining code.

2. Try…Catch Syntax

try block contains code that might throw an error.
catch block handles the error gracefully.

3. Finally Block

Optional finally block always executes, whether an error occurs or not.

4. Throwing Custom Errors

You can create your own errors using throw.

5. Practical Uses

Validate user input in forms.
Handle API request failures.
Ensure smooth execution in interactive applications.

✅ Summary:

Try…catch handles errors gracefully.
Finally block executes always.
Throw lets you generate custom error messages.
Proper error handling is crucial for robust web applications.