Although it will depend on how many sugary snacks you are eating and how often, overall, sugar is bad for your health, so you shouldn't have too much of it.
Primarily the problem is that anything that contains sugar will have a lot of calories in it. So you will have to make sure that you are eating everything in moderation so as not to go over your guideline daily amount of calories.
Sugar also increases your blood sugar level which, when it gets too high, can give you an increased risk of other health problems, such as heart disease.
If you are eating a lot of sugar, it is more likely that you will put on weight, as chances are if your'e snacking on unhealthy sugary foods, then you are not eating foods that are good for you such as fruit and vegetables.
Another problem with eating too many sugary foods is that it is bad for your teeth. Sugar promotes tooth decay, so the more sugary foods that you eat, the more likely that your teeth are to decay. This fact has been proven by simply putting a tooth in a sugary drink, and watching it decay in as little as a few hours.
So if you are craving something sweet, maybe replace that craving with a piece of fruit, which contains natural sugars also essential vitamins and minerals for your diet. Of course treat yourself now and again, but make sure it is part of a balanced diet because an excess of sugar can definitely be a heath risk.