Here are a few programs that use the fundamentals of object oriented programming in java
Secret Santa This program allows you to draw names for secret santa instantly. Some of it's features include a wishlist for every person, a password to ensure privacy, and unlimited participants.
Secret Santa uses a main class named SecretSanta to perform the main tasks.This includes inputting names, and outputing the results. This program also uses another class named Participant. This class creates objects that store each participants name, draw name, password, and wishlist.
FracCalc FracCalc adds, subtracts, multiplies, and divides fractions. It takes in an operator and two fractions and outputs the result in the simplest fraction form.
The Fraction class in this program creates an object to store the fractions denominator and numerator. It also has several algorithms that allow you to calculate using fractions.