Redux on functional components in Reactjs (web)

As of version 7.x react-redux now has hooks for functional components.

Header.jsx

import React from 'react';
import withStyles from 'isomorphic-style-loader/lib/withStyles';
import s from './Header.css';
import { Navbar, Nav } from 'react-bootstrap';
import HeaderMenu from '../HeaderMenu';
import cx from 'classnames';
import { useSelector } from 'react-redux'

function Header() {
  const store = useSelector(store => store)
  return (
    <Navbar fluid fixedTop id="Header" className={s.navContainer}>
      <Nav block className={cx(s.HeaderTitle, s.hideOnSmall)}>Project title</Nav>
      <HeaderMenu />
    </Navbar>
  );
}

export default withStyles(s)(Header);

index.js

import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import { Provider } from 'react-redux'
import store from './store'

ReactDOM.render(
    <Provider store={store}>
        <App />
    </Provider>,
    document.getElementById('root')
);

As Dan Abramov mentioned in his insanely famous Egghead.io series, presentational component shouldn't be aware of Redux store and shouldn't use it directly. You should create something called container component, which will pass necessary state fields + action callbacks to your presentational component via properties.

I highly recommend to watch Dan Abramov's Egghead.io series if above concepts are not familiar to you. Patterns he is describing there are de facto standard style guide for writing React+Redux applications nowadays.