Stop Overusing Inheritance: Choose Composition

In object-oriented programming, inheritance and composition are two classic techniques to reuse code and establish relationships between classes. For decades, many developers have been taught that inheritance is the go-to solution for sharing behavior. But in real-world systems, inheritance often creates more problems than it solves. At Eclipsos Corp., we encourage teams to rethink that default and lean on composition whenever possible.

The Core Concepts

• Inheritance: Creates an is-a relationship. A Dog class inheriting from an Animal class means a Dog is an Animal. Shared behavior flows down from the base class.
• Composition: Creates a has-a relationship. A Car class with Engine and Wheel instances means a Car has an Engine and has Wheels. Behavior is delegated, not inherited.

Both patterns promote reuse, but that’s where the similarity ends.

The Problem with Inheritance

• Tight coupling: Change the base class and risk breaking every subclass.
• Fragile hierarchies: Deep chains of inheritance make code harder to follow, test, and maintain.
• Multiple inheritance headaches: Languages that allow it introduce the infamous diamond problem.

We see it all the time: teams locked into rigid class trees that resist evolution. What once felt like a shortcut turns into technical debt.

But Why Keep Adding Inheritance?

If we already know inheritance introduces tight coupling—where a change in a base class can ripple through and break dozens of subclasses—why do developers still reach for it?

The answer is mostly habit and convenience. Inheritance feels like a shortcut: you get ready-made methods and properties without extra wiring. It’s quick to set up, it looks clean at first glance, and it’s what many of us were taught in our first programming courses.

But those short-term gains come with long-term costs. Every time you inherit, you lock your new class to the internal decisions of the parent class. You create hidden dependencies that make refactoring risky. Over time, you trade flexibility for fragility—and the system pays the price.

At Eclipsos Corp., we challenge this mindset. Convenience should never outweigh maintainability. Instead of asking “how can I reuse this base class?” we ask “how can I compose this behavior in a way that keeps my system adaptable?”

Why Composition Is Better

• Looser coupling: Each piece is independent, easier to swap or modify.
• Greater adaptability: You can combine behaviors without rigid hierarchies.
• Avoids inheritance pitfalls: No diamond problem, no hidden base-class surprises.

Yes, composition can mean a bit more wiring code. But the trade-off is worth it. Your architecture remains cleaner, easier to extend, and far less likely to collapse under future changes.

When to Use Each

• Use inheritance only when there’s a crystal-clear is-a relationship and your subclass is truly a specialized form of the base class.
• Use composition in almost every other case—especially when flexibility, testability, and long-term maintainability matter.

Final Thoughts

Modern software systems demand adaptability. At Eclipsos Corp., we believe clinging to inheritance because it feels familiar is a mistake. Composition may ask for a little more thought upfront, but it pays off with simpler, more resilient designs.

It’s time we stop treating inheritance as the default and start building software that can grow with us—not against us.