Click Event in React Js

 import React from 'react'

const User = () => {

    let data = "Lutfor Rahman Hera";

    function apple()

    {

        data = "Didar";

        alert(data);

    }

  return (

    <div>

        <h1>{data}</h1>

        <button onClick={apple}>Click Me</button>

    </div>

  )

}

export default User;