Can you tell me is eating a chocolate bar or candy every night bad for you?

Probably not: Candy supplies calories and little else. If the amount of calories which you eat prior to going to bed, does not exceed your needs there is no harm. Some feel that eating late, candy or otherwise, contributes to acid reflux and the development of esophageal disorders, so you might consider eating the candy, if you must do so, earlier in the evening.