Why would you need two or more versions of jquery on the same page?

Question

JavaScript

Repeatedly found a similar story and ways to coordinate them in the form, for example, noConflict. Especially in wordpress. Why might this be needed? As an option, to ensure the work of some old plugins? Or for something else?

Answer 1

For shit code, of course

Answer 2

to support existing functionality and new ones.
situations are different. for example, you have a working service that was implemented in 13-14 and you want to add something new to the current version and not write, at the same time, everything from scratch. That's when several versions are connected.

Answer 3

I personally had a slider a year ago that worked on jquery 1.8 , but before that I already had a bunch of libraries connected that support jquery 1.13. So I had to put two versions. But it sucks to do that.