Type Alias SetStateAction<S>

SetStateAction: S | ((prevState: S) => S)

The instruction passed to a Dispatch function in useState to tell React what the next value of the useState should be.

Often found wrapped in Dispatch.

Type Parameters

S
The type of the state.

Example

// This return type correctly represents the type of
// `setCount` in the example below.
const useCustomState = (): Dispatch<SetStateAction<number>> => {
  const [count, setCount] = useState(0);

  return setCount;
}