Class vs Functional Components in 2025: Should You Still Learn Both?

Class vs Functional Components in 2025: Should You Still Learn Both?

Beginners ask whether they need to learn both class and functional components in 2025. The honest answer is nuanced. Here is what each is good for.

Functional Components: The Default

Functional components with hooks are how all new React code is written. They are simpler, have no this binding issues, and let you extract reusable logic into custom hooks. This is what you write.

Class Components: For Reading

Class components are what older codebases use. You will encounter them in legacy projects, in tutorials made before 2020, and in interview questions about lifecycle methods. This is what you read.

Should You Learn Both?

Yes, but with different depth. Learn functional components deeply because that is what you write. Learn class components enough to read them and answer interview questions, not to write them from scratch.

The Lifecycle Knowledge

The main reason to learn class components is the lifecycle. Understanding mount, update, and unmount phases, and how they map to useEffect, deepens your understanding of how React works even when you only write hooks.

The this Problem

Class components rely on this, which causes binding issues that beginners struggle with. Knowing this exists helps you appreciate why the React team moved to hooks, and helps you read old code without confusion.

The Takeaway

Learn functional components deeply. Learn class components enough to read them and pass interviews. The lifecycle knowledge transfers to your understanding of hooks, so it is not wasted effort.