Companies are obliged to put expiration dates on things. I have coffee in my cupboard that expired 2003 and it is fine. Most sugary things have so much sugar in that they also won't go bad till way after their expiration date. I have some jam that is a year out of date and sauces that are months out. They taste the same as new ones, and they have never made me sick.
Some companies also put expiration dates long before the date the item would actually be bad, so that if it is something you don't use often, it forces you to buy more, so that the company gets more money.
Having said all this, I am careful about what I do and don't use after expiration. Biscuits, chips, etc, should be fine, but they don't taste any good after a while, so I don't keep them long after expiry. Jam, honey etc - no problem. Eggs and milk - ICK - like most people I don't even use these things on the DAY of expiry. Way too scary.
As for chocolate, well I have never kept that in my house long enough to pass the expiry, so no idea about that! =D