Replacing mapStateToProps with the useSelector Hook

Redux provides a useSelector hook for easy access to state within a function component. This hook replaces the mapStateToProps function which was used previously with connect(). The hooks API is a lot simpler and can be combined nicely with selector functions.

The basic API looks like this:

const value = useSelector(state => state.reducerName.value)

When used with a selector function it looks like this:

const value = useSelector(getValue)