Will Wordpress updates overwrite code I customised?

Question

I use a Wordpress theme that I have customised a lot. If I update Wordpress or the theme that I'm using, will it overwrite the code I customised in the theme or Wordpress system? Or can I just update everything.

Same with Wordpress plug-ins: I've written some extra code in the Woocommerce's cart script. If I update WooCommerce, will it be lost or overwritten?

Answer 1

Yes if you update the plugins and themes, those will be overwritten and you will lose the changes you made.