How can fruit in a plastic jar stay fresh for so long?

I just bought these pineapple slices, they are in a plastic jar and it says they are mixed with corn syrup. How does fruit not go bad for years? I thought fruit couldnt last that long. Did they add something else to it?

How can fruit in a plastic jar stay fresh for so long?
It won't last for years. Canned fruit and fruit juices may be stored in a cool, dry place below 85°F (optimum 50°F to 70°F) for one year, if the seal on the container hasn't been broken.