Ya, canned food doesnt go bad. Foods can only go bad if bacteria gets in there but unless the can has been opened, it wont go bad!

Canned food has a shelf life of at least two years from the date of processing. Canned food retains its safety and nutritional value well beyond two years, but it may have some variation in quality, such as a change of color and texture. Canning is a high-heat process that renders the food commercially sterile. Food safety is not an issue in products kept on the shelf or in the pantry for long periods of time. In fact, canned food has an almost indefinite shelf life at moderate temperatures (75° F and below). Canned food as old as 100 years has been found in sunken ships and it is still microbiologically safe! We don't recommend keeping canned food for 100 years, but if the can is intact, not dented or bulging, it is edible. http://www.foodreference.com/html/tcannedfoodshelflife.html

Experation dates on food tends to er on the conservative side. This is for 2 reasons. firstly so they get more sales and secondly so that they don't get sued stupid if it does go bad. I know Chalet suzanne in Florida who can thier own soup have cans that were canned over 40 years ago and it's aparently as fresh as the day it was cooked.

Canned food can and does go bad. Canning is a good process, and eliminates much bacteria and oxygen. However, there is still the issue of anaerobic bacteria: These little beggars are slow to grow normally, but they can do so in the absence of oxygen. What's more, they can make you incredibly sick. Modern canning is quite good, but as for expiry dates, take them a grain of salt. They err on the side of safety, and often the only thing that's "wrong" is the destruction of nutrients, flavour or texture. Still, if something looks off, smells off or tastes off, don't eat it.

Canned food generally is edible long after its expiration date (see the other answers) however it is often not as good. The food breaks down over time even without bacteria. I had a can of cranberry sauce I got when my grandmother died that was, by the time I opened it, about three years past its expiration date. It was a bit browner and more solid than it should have been and I did not eat it. It smelled fine, but the texture and color were all off.

HOW LONG IS A CANNED FOOD GOOD FOR AFTER EXPIRATION?

Canned food is pretty safe from bacterial action. but there can be exceptions of fx production temperatures were not correct. That is usually what causes 'bulging' cans. Canned food is not necessarily safe from chemical reactions. The metals used in the can may react with the food and contaminate it. If the can is sealed with a solder containing lead the lead could diffuse into the food and that is not healthy. cans older than about 20 years were made with metals only and should not be trusted. Modern cans are usually made with an inner polymer lining to avoid such contamination, but even there production errors can give rips or holes in the lining so metal and food can get at each other. And finally cans can corrode from the outside until holes appear through which bacteria and whatever can get at the food. Heat and moisture accelerate corrosion and chemical reactions so storage in a cool dry place improve the odds of the can staying good. You can be lucky and have a can that is still eatable after hundreds of years, but you can also be unlucky and get a can that has gone bad after a few years. maybe even before the expiration date. So it is not true that cans 'never really go bad'. At least not without a lot of caveats: perfect production, cool dry storage, non acidic food, etc.

The food will decompose. The daye is based on studies of when 1 in (??) so many cans has enough deterioration to be unsafe/unhealthy. The date is very conservative, so I never hesitate to eat canned food a week-month old. This does not apply to opened products or packaged meat.

7-1-2017 Food products are required to have an expiration date and it depends mostly on the packaging materials. For instance, bottled water expires when some politician guessed the plastic chemicals would leach into the water. Food does not "go bad", it's only that some critter eats it before you do. A can swells when that happens. Bread mixes containing shortening go bad when the shortening absorbs oxygen, which happens when the package gets punctured. You can smell when that happens. It is a prominent odor. Other than those things, packaged food stays good forever.