handling state in functional components reactjs ijnterview questions
function ClassRoom(props){
 let [studentsCount,setStudentsCount] = useState(0);
 const addStudent = () => {
   setStudentsCount(++studentsCount);
 }
 return(
   <div>
     <p>Number of students in class room: {studentsCount}</p>
     <button onClick={addStudent}>Add Student</button>
   </div>
 )
}