jQuery Error: Uncaught TypeError: Illegal invocation

When dealing with jQuery, you might encounter the error "Uncaught TypeError: Illegal invocation" at certain times. This error is usually caused by a mistake in your code, and it can be difficult to trace the exact source of the error.

What does it mean?

When JavaScript encounters an "Illegal invocation" error, it means that a function was called incorrectly. In the context of jQuery, this usually means that a function was called on an incorrect object or with incorrect arguments. In other words, the function was called in a way that it was not designed to be used.

Common Causes

1. Wrong Selectors: jQuery selectors are case sensitive. If you pass a string as a selector but have used the wrong case, then jQuery will return null, which in turn can lead to the illegal invocation error.

2. Incorrect Usage: Some jQuery functions are meant to be called on specific elements or objects. Calling these functions on something else, such as a plain JavaScript object, can lead to the illegal invocation error.

3. Old version of jQuery: You may have an old version of jQuery that has known bugs, including issues that could lead to the illegal invocation error. Consider upgrading to a newer version.

How to debug this error?

To debug this error, the first step is to identify the code that is causing it. Check the console log to see which file and line the error is being thrown from. Then, examine the code in that area and review the possible causes listed above to identify where the problem may lie.

Also look for other error messages which might have been logged before this error. They might be able to provide helpful hints and help you identify the real problem.

Conclusion

The "Uncaught TypeError: Illegal invocation" error in jQuery is usually caused by a small mistake in your code. If you are careful with your use of selectors and function calls, and keep your jQuery version up to date, you should be able to avoid this error altogether.