Should you learn JavaScript before React?
Yes — at least the essentials. React is JavaScript, so concepts like functions, array methods, destructuring, promises/async-await, and the event loop appear constantly. Spending time on modern JavaScript (ES6+) first makes React click much faster and prevents the confusion of learning two things at once. You don’t need to master everything, but a working command of the fundamentals pays off immediately.
How does React actually work?
React builds UIs from components — reusable functions that return markup. Each component can hold state, and when state changes, React efficiently updates the DOM to match. Hooks are the modern way to add capabilities to function components: useState for local state, useEffect for side effects like data fetching, and others for context, refs, and memoization. Thinking in components and state is the core mental shift.
How do you manage state in React?
Start simple. Use local component state for UI that only one component needs. Lift state up to a shared parent when siblings need it, and reach for the Context API for app-wide values like theme or auth. Only add a dedicated state-management library when your app’s shared, frequently-changing state genuinely outgrows these built-ins — premature libraries add complexity you don’t need.
Why is my React app slow?
Most performance problems come from unnecessary re-renders — components updating when their data hasn’t meaningfully changed. Understanding when and why React re-renders, then applying memoization (memo, useMemo, useCallback) and stable keys where they matter, resolves the majority of issues. Measure first with the React DevTools profiler rather than optimizing blindly.
How should you practice?
Build projects that use real patterns: a todo app for state, a data dashboard for fetching and effects, a form for controlled inputs. Each reinforces a core concept. Read component code, refactor as you learn, and add tests. Project-driven practice turns React knowledge into the muscle memory employers look for.