When potassium and fluorine bond what kind of bond is it?

I remember that by thinking of table salt. Basic Na(Sodium) and Cl(Chlorine) one is a metal the other is a non-metal. They have an ionic bond; same as potassium and fluorine. I remember the difference between ionic and covalent by this someones answer which said "the names bond. Ionic bond, taken not shared" Its silly but it works :)