So many of us really love to eat pineapple. Strangely the only place I like my pineapple is on my pizza, and I save money by buying a Queen pineapple (the kind without the serrated leaves) because they're larger and sweeter, and when I get home I cut off the top and put it into a glass of water on the windowsill.
Then to store pineapple long-term I cut the spiky skin off (put that in the compost), and dice the entire pineapple into small cubes - and freeze handfuls in ziploc bags. This makes adding it to pizza, stir-fry, and sweet & sour sauces so easy (and you don't have to buy tinned or wait for it to be in season.)
I have an addiction to growing food, I can't help myself, and I do this every time I get an avocado or pineapple - I simply have to get it to root.
Keep an eye on your pineapple leaves in the glass, never let the bottom cluster get dry, and if there is any pineapple fruit still stuck on there make sure to take it off or it will cause rotting. Change the water once a week if need be.
It takes about 3 weeks to get this many roots. Once you've got a decent length of root, plant it in a sunny position with lots of composted soil. And in 2 years time you'll have pineapples!