This week's book giveaway is in the OCAJP forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide 1Z0-808 and have Jeanne Boyarsky & Scott Selikoff on-line! See this thread for details.
If you are referring to integer types, then try to print it out before you increment it. You will notice that it is printed as 1 and not 0001. Integer types do not have a format, you'll need to add it yourself during printing.