how often are hooks used in react code example

Example 1: why we use hooks in react

import React, { useState, useEffect } from 'react';
function Example() {
  const [count, setCount] = useState(0);

  // Similar to componentDidMount and componentDidUpdate:  useEffect(() => {    // Update the document title using the browser API    document.title = `You clicked ${count} times`;  });
  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>
        Click me
      </button>
    </div>
  );
}

Example 2: how to use hooks react

const App = () => {
const [students , setStudents] = useState([]);
  
  return (
// put in the jsx code here
  )
}