Onboard toilets

Hi,

Do trains such as those on the Gotemba or Tokaido line that travel longer distances have toilets onboard?
I know most stations have facilities however it would be inconvenient to disembark and possibly have to wait for a later train just for a toilet break.
No websites have had any information about toilet facilities onboard for non-shinkansen trains from searching online.

Kind regards
Indigo