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React Components & State - React & Next.js Frontend Foundations | Aporeon

React & Next.js Frontend Foundations

React Components & State

Props, state, controlled inputs, derived state, keys, batching, and component boundaries.

8 drillsPractice one at a timeOrdered pathConcept questionArchitecture scenarioComparison question

Recommended start

Rendering, Props, State

Explains how React components render from props and state, and how updates flow through a component tree.

Easy~5 minStep 1 of 8

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1Rendering, Props, StateRecommended startExplains how React components render from props and state, and how updates flow through a component tree.Concept questionEasy~5 minReactTypeScriptPractice 2

Practice order

8 drillsOne at a time

1Rendering, Props, StateUp next / Easy / ~5 min
2Controlled InputsEasy / ~5 min
3Derived StateMedium / ~7 min

Controlled InputsExplains controlled inputs, uncontrolled inputs, validation, refs, and when each form approach fits.Concept questionEasy~5 minReactTypeScript

Practice

3Derived StateExplains when to derive values during render instead of storing duplicate state that can drift.Concept questionMedium~7 minReactTypeScriptPractice

4Keys and IdentityExplains why list keys matter for reconciliation, state preservation, reordering, and predictable UI behavior.Concept questionMedium~7 minReactTypeScriptPractice

5State Update MechanicsExplains asynchronous-looking state updates, batching, functional setters, and avoiding stale values.Concept questionMedium~7 minReactTypeScriptPractice

6Component BoundariesExplains how to split components around ownership, reuse, readability, state, and API-like prop contracts.Concept questionMedium~7 minReactTypeScriptPractice

7State OwnershipPlaces state according to who owns it, how long it must live, and whether the URL or server is the source of truth.Architecture scenarioMedium~10 minReactTypeScriptPractice

8React ReducersExplains when a reducer clarifies related state transitions and when independent state remains simpler.Comparison questionMedium~7 minReactTypeScriptPractice

4Keys and Identity

Medium / ~7 min

5State Update MechanicsMedium / ~7 min

6Component BoundariesMedium / ~7 min

7State OwnershipMedium / ~10 min

8React ReducersMedium / ~7 min