how to set state value in class component code example

Example 1: props and state react

function tick() {
  const element = (
    <div>
      <h1>Hello, world!</h1>
      <h2>It is {new Date().toLocaleTimeString()}.</h2>
    </div>
  );
  ReactDOM.render(    element,    document.getElementById('root')  );}

setInterval(tick, 1000);

Example 2: reactjs update state example

{
  hasBeenClicked: false,
  currentTheme: 'blue',
}