JS Built-ins
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redux-toolkitcreateEntityAdapterintermediate

Entity Adapter Selectors

📖 Usage Example
const selectors = adapter.getSelectors(state => state.items)
selectors.selectAll(store.getState())     // → [{ id: 1, name: 'Widget' }, ...]
selectors.selectById(store.getState(), 1) // → { id: 1, name: 'Widget' }
selectors.selectTotal(store.getState())   // → 1

getSelectors generates pre-built selectors scoped to the entity slice — selectAll, selectById, selectTotal, and more.

Entity Adapter Selectors

adapter.getSelectors(stateSelector) returns a set of selectors: selectAll, selectById, selectTotal, selectIds, and selectEntities.

Challenge: Create a store and use adapter selectors to query items.

selectors.selectAll(store.getState())        // → [...]
selectors.selectById(store.getState(), 1)    // → { id: 1, name: 'Widget' }
selectors.selectTotal(store.getState())      // → 2
💡 Hints (3)
  • • `adapter.getSelectors(stateSelector)` scopes all selectors to the given state slice.
  • • `selectAll` returns all entities as an array in `ids` order.
  • • `selectById(state, id)` returns the entity for that id, or `undefined`.