Using Custom Events as a web component API

May I ask why it is you define ids but then use querySelector('#id')? Isn't it more efficient to use getElementById('id')?

Overall a well thought out tutorial a well presented. Thank You

Thanks for the feedback Denys :) Regarding your question:

May I ask why it is you define ids but then use querySelector('#id')? Isn't it more efficient to use getElementById('id')? Performance was not the point of the lesson and querySelector was what I came up with at the time. When writing your app you should consider optimizing when needed. In this case, I query for 3 elements only once so it would be microoptimization to take this into account. If you are optimizing in a for loop, then you'd might have performance implications. See this jsperf for reference: https://jsperf.com/queryselectorall-vs-getelementbyid/35 Cheers!

I really appreciate your response and for taking time out to find and the link , the results of which I found quite interesting.

Thank you

Denys