state-hooks
Version:
Essential set of React Hooks for convenient state management.
16 lines (15 loc) • 440 B
TypeScript
/**
* Tracks previous state of a value.
*
* @param value Props, state or any other calculated value.
* @returns Value from the previous render of the enclosing component.
*
* @example
* function Component() {
* const [count, setCount] = useState(0);
* const prevCount = usePrevious(count);
* // ...
* return `Now: ${count}, before: ${prevCount}`;
* }
*/
export default function usePrevious<T>(value: T): T | undefined;