Context value
A context value is data supplied by a React context provider and made available to descendant components that consume that context.
React Quickly, Second Edition
A context value is the data stored in React Context and made available to components that consume that context.
- How it is used
- Shares data and behavior across a component subtree without threading props through every intermediate component.
- How deep it goes
- Explains creation, provision, consumption, defaults, objects, custom hooks, and reactive updates, but does not detail performance optimization.
- Examples
- Uses menu links, an administrator dashboard, selected users, authentication state, API access, and object-shaped provider values.
- What you can do after
- Apply it via React createContext, Context.Provider, useContext, useState, and custom hooks to share changing application data.
Read how React Quickly, Second Edition explains context value →
React in Depth
A context value is the data supplied by a React context provider for access by consuming components.
- How it is used
- Coordinates shared state and actions, such as dark-mode status and toggling, across consuming React components.
- How deep it goes
- Explains object values, consumer re-renders, memoization, TypeScript inference, and explicit context typing; it stops short of selector-based contexts.
- Examples
- Uses light/dark mode with a Boolean value, then an object containing mode and toggle.
- What you can do after
- Build it from scratch by defining, providing, consuming, typing, and performance-tuning a context value.
Related concepts
- useContextused by · useContext is a React Hook that reads the current value of a context from the nearest matching provider or its default value.
- booleankind of · A Boolean is a logical type or value representing truth or falsity, conventionally with two states: true and false.
- provider patternproduced by · The provider pattern is a design pattern in which a component or service makes shared data or capabilities available to descendant components or dependent consumers.
- objectused by · A computational object is a runtime entity or structured value representing data, state, or a resource, with properties or operations defined by its programming model.
- React contextpart of · React context is a mechanism for making values available to descendant components without explicitly passing them through intermediate components.
These guides are generated from the text of Manning books by Manning's knowledge graph and link to the sections they draw on. The full books are available on liveBook and at manning.com.