It can be formed by sharing electrons. Is this true for all compounds or just salt?

Salt of sodium Chloride is a ionic body because alkali metals like to either give or accept electrons and chlorine likes to do the same ones electro negative and the other is less electronegative that gradient is enough for then to bond, some elements like to do the same thing like fluorine is nasty stuff it reacts with everything meaning it gives off electrons alot more to become a compound with another element