How do you say bye in french?

Of course the standard way to say goodbye in French is

au revoir -- "oh r(ee)-vwar" (sounds in parentheses are optional)

But there are many informal variations, such as

salut -- "sah-lew" -- probably the most common; also means "hi"

bye-bye -- borrowed from English; pronunciation is meant to be the same as English, but since the French have trouble with our gliding diphthongs, it ends up sounding more like "bah-ee-bah-ee"

ciao -- "chah-oh" -- borrowed from Italian; alternate "French" spelling tchao

à demain __"ah- deman" means until tommorow