>>...i just a jump start a hint to make it work. and i only need to use while loop.
I gave you a hint. Here's another:
Don't use the decrement operator. Use the increment operator instead, then adjust your loop's control condition accordingly.
If you have to use a while loop, it's doable, just less convenient.
i am trying to create a library management system which is supposed to be used to store/keep infp for the library and the library members( book title, author, name and picture for borrower and other stuffs). The app has 6 buttons, delete, save, add,previsous,next, and upload( for upload ...