usePrevious

API

import usePrevious from '@restart/hooks/usePrevious'

usePrevious<T>(value: T) => T | null
Store the last of some value. Tracked via a Ref only updating it after the component renders. Helpful if you need to compare a prop value to it's previous value during render.
```
function Component(props) {
  const lastProps = usePrevious(props)
  if (lastProps.foo !== props.foo)
    resetValueFromProps(props.foo)
}
```
Parameters
- valueT
  the value to track
Return Value T | null