The main benefit of classes is as a way to define custom types. Otherwise you are stuck with the types built into the language, which are not designed to help ensure correct program state, logic, and behavior. When you use classes in this way, I call it type oriented programming (TOP). Why would I compare classes to types? Just pass in the initial value at construction time, define the "operations" on that type by creating methods for your class, and define which other types those operations work with by setting the types of parameters those methods work with. Make the class immutable, always returning a new instance with the new updated value passed into the constructor. Why did I mention these types helping the program be more correct? This should be used as the primary form of contracts. But these contracts are very simple to use, you just specify the relevant type in the parameters and return values, and you are done defining the contract for any given method. For example, let's say a method should only work with integers larger than zero, instead of either accepting an Int or an UnsignedInt, which would allow 0, you could define your own class called PositiveInt. It would be designed to throw an exception if you pass anything smaller than 0 into the constructor. Then instead of writing code inside the method that makes sure the user of the method is following the contract, you just specify PositiveInt as the parameter type. If the contract is violated, the exception will be thrown as early as possible, before the method is even called, helping programmers catch the original source of the problem. This also makes your code more readable, because you can see exactly what each method accepts and returns just by looking at the method signature. When you start thinking this way, you will notice many core types are missing from the language, that should have been there from the beginning. Fortunately you now know how to build them yourself.