Can a nail hardener count as a base coat?

I've never used a base or top coat. Recently I've been told it is important. I don't have either of them, but I do have a nail hardener by sinful colors.Can a nail hardener count as a base coat?
It is important to always wear a base coat as a dark polish can discolour your nails and make them go yellow. A nail hardener could be used as it is still providing a protective barrier between the nail and the polish :-)Can a nail hardener count as a base coat?
I use Sally Hansen's nail hardener as my base coat and it works great for me. I think it all depends on how picky you are...I use 2 coats of nail hardener as a base coat, then nail polish and OPI's top coat and it looks great!
barry m have a base coat top coat and nail hardener all in one =) and at the moment they are doing any two nailvarnish (barry m) for a fiver ! =)