When is it recommended to use a class in programming?

A class is recommended to be used when you need to combine data and methods that operate on that data into a single structure. This is convenient for modeling real-world objects or abstractions, allowing encapsulation of state and behavior. In iOS development, classes are especially useful when inheritance, working with reference types, or utilizing Objective-C runtime features (such as delegates, KVO) are required. If an object needs to have mutable state and be passed by reference, a class is the right choice.