This question is quite prevalent for beginners, and it's good that someone has raised it here in the knowledge base.

How good is W3Schools for learning Javascript?

To me, it's a great resource to learn about javascript but not so great to learn Javascript itself. I say this because W3Schools does a great job at covering the basics, but it doesn't go beyond that, and I suppose, it is not meant to go any further either. To learn Javascript is a long process and to build complex applications, you need to dive deep. W3School provides a dictionary sort of approach to give simple explanation about Javascript API.

You could compare it to primary school, where kids learn the vocabulary, and they go on to the higher classes and learn more important subjects. In the same way, W3Schools helps you get started on the journey of Web development, and its role ends there. You need to carry that forward to further your understanding to build useful applications using Javascript.

For me, W3Schools serve two purposes:

1. As a platform, to make your acquaintance with Javascript, test the water so to speak.

2. For quick reference: I indeed use W3Schools even after years of experience as a Frontend developer. I use it to test out basics at times. For instance, just today I looked for some information on the third param in event listener ele.addEventListener('click', handler, false)
What is the third parameter ‘false’ for? I still get these basic questions and W3School does a good job at providing quick answers. Though not my goto resource, I often stumble upon w3schools when it comes to basics.

I hope W3Schools continues their good work and contribute to world in the same way.