Hydrogen has only one electron in its electronic configuration. If it loses that electron, It will have only positive charge which will make it highky unstable. If it gains 1 electron, the effective nuclear charge on it will become 2 which will again make it highly unstable. To deal with this problem, hydrogen shares electrons to form compounds. So, no compound of Hydrogencan be an Ionic compound in normal case. So, Hydrogen chloride is also a covalentcompound.