Salt is added to pineapple in several countries because it neutralizes the acid. These pineapples, not like the ones we have in Europe and the American continent (guessing here), are so acid they can burn your tongue.
Padlock Hole - Have you ever wondered why there's a hole on the bottom of padlocks? Well, it's there to let water drain out of the lock when it's being used outdoors. This way, the lock won't rust from rain or freeze from cold weather.
Salt is added to pineapple in several countries because it neutralizes the acid. These pineapples, not like the ones we have in Europe and the American continent (guessing here), are so acid they can burn your tongue.