[Guest]

Those are Countries First Jet Aircraft/Experimentals and so they are not fighters.

Gloster-Whittle was a fighter, it had provisions for 4 x .303 Brownings.

He-280 was also a fighter.

Ikarus J-451MM was a fully equipped light attack aircraft.

These are no different than some of those already listed that didn't go beyond a handful of prototypes.

Gloster Wittle may have had room for guns but I'm sure with a few adjustments you could have a stuck 20mm cannon in the He-178.
Besides it's role was an experimental prototype, it was never intended for combat, it was a test bed for Englands First Jet Engine, why would they jump to conclusions after one flight and stick guns on it.
He-280 was indeed a fighter, that never got past the prototype stage.

I really think the titles of this topic would mean operational fighters, not prototypes that were never going to enter combat, and if they did, well they would be called something else and it would be a different plane with a different role.