useEffect(() => { title = name + ' ' + lastname; });

useEffect(function updateTitle() { name + ' ' + lastname; });

useEffect(function updateTitle() { title = name + ' ' + lastname; });

useEffect(function updateTitle() { document.title = name + ' ' + lastname; });

useEffect(() => { title = name + ' ' + lastname; });

useEffect(function updateTitle() { name + ' ' + lastname; });

useEffect(function updateTitle() { title = name + ' ' + lastname; });

useEffect(() => { title = name + ' ' + lastname; });

useEffect(function updateTitle() { name + ' ' + lastname; });

useEffect(function updateTitle() { title = name + ' ' + lastname; });

useEffect(function updateTitle() { document.title = name + ' ' + lastname; });

useEffect(() => { title = name + ' ' + lastname; });

useEffect(function updateTitle() { name + ' ' + lastname; });

useEffect(function updateTitle() { title = name + ' ' + lastname; });

useEffect(function updateTitle() { document.title = name + ' ' + lastname; });

class clock extends React.Component {
  render() {
    return <h1>Look at the time: {this.props.time}</h1>;
  }
}

useEffect(function updateTitle() { document.title = name + ' ' + lastname; });

useEffect(() => { title = name + ' ' + lastname; });

useEffect(function updateTitle() { name + ' ' + lastname; });

useEffect(function updateTitle() { title = name + ' ' + lastname; });

useEffect(function updateTitle() { document.title = name + ' ' + lastname; });