State lifting in React is a technique where the state is moved from child components to their closest common ancestor component. This is done so that multiple components can share and synchronize the same state data effectively. Instead of each child component maintaining its own local state independently, the shared state is "lifted up" to a parent component, which becomes the single source of truth. The parent then passes the state down to the children via props, and also provides callback functions to update the state. This ensures that all components stay in sync and reflect the same data consistently
. For example, if you have two input components that need to display and update the same value, lifting the state up to their parent component allows both inputs to stay synchronized. When one input changes, the parent updates the state, and the new value is passed down to both inputs, keeping them consistent
. In functional components, this is often done using the useState hook in
the parent, which manages the state and passes both the state value and the
setter function down to child components as props
. In summary, lifting state up:
- Moves state from child components to their nearest common ancestor.
- Creates a single source of truth for shared state.
- Allows multiple components to stay in sync by sharing state via props.
- Improves data consistency and component communication in React applications
