Fundamental Javascript Question about ID's and the DOM

[Jim Nayzium]

Is it bad to have two elements with the same id= and be targeting them both with javascript innerHTML updates, if only ONE of them is ever visible to the page because of media queries? I am setting the display:none and display:block with media queries to make sure and I am updating their HTML simultaneously on the page with javascript with the same script. But I only ever have ONE of them showing to the page. I have it all working but was curious if I should be writing the extra lines to update two div_id's innerHTML since they are "in the running code of the page" but are not "displaying" etc...

 

The only time I feel like it's an issue is when someone resizes their screen live while viewing the page and I would need the javascript to re-run. But other than that, I was just wondering what best-practices dictate in this case above?

 

Sorry for the fairly newb/javascript level question.

[elegantseagulls]

It's bad semantic HTML to use the same id on multiple items an id is supposed to be a unique identifier. You may consider using a class for these instances where you need to style/target multiple elements. More on that here: https://css-tricks.com/the-difference-between-id-and-class/