Why is my IPhone 4 camera not working?

My camera stopped working like 2 weeks ago, the shutter won't open, but when I use snap-chat only my front camera works, I don't know what happened? I tried everything, resetting the phone everything and its still not working. What can I do? It really annoying.

If you have reset the iPhone it is most likely a hardware issue more than a software issue. If the phone is past its 1 year manufacture defect warranty i'd suggest getting a new phone. If you have an extended warranty I'd suggest getting it fixed. You can alternatively opt to send it to apple however this can range up into the $200 range for repairs (not including shipping and handling) if you have just reset it by turning it off and on again try this.

1. Plug the iPhone into iTunes.
2. Restore it to factory default settings (do a back up if you don't wish to lose your data)
3. If this STILL does not solve the problem it is most likely hardware related issue, even if you haven't dropped it or anything these devices do break down

Your memory card might be corrupted.

If you're lucky, you just need a reset of your settings. Go to Settings > General > Reset (At the bottom), just make sure to select Settings only and not content. After reset check your camera app again, if it works enjoy!

Now if it does not work, you're in trouble. Many iPhone 4 came with a bug that once you have taken it apart and put it together, the camera app will simply not open and glitch in the bottom right corner. This typically is because of the front facing camera, in fact it occurs when you switch from your rear camera to your front facing camera. A simple reset of settings will help you restore functionality to your rear camera however your front camera will be permanently useless. No way to fix it asides from replacing the connector on the logic board or getting a warranty exchange.

I had same problem - brand new iphone4.camera "shutter" wouldn't open.
Hold down the home button and the top button. Turn it back on and as soon as it reboots, do the same thing again.
If your iphone is in warranty then, better take apple service to fix this.