1.
import React, {useState, useEffect} from 'react';
const Counter = (props) => {
const [userMail, setUserMail] = useState('this@daum.net');
const [counter, setCounter] = useState(0);
return (
<>
<h1>{props.userName}</h1>
<h1>{userMail}</h1>
<button onClick={() => setUserMail('wegosky')}>버튼</button>
<h1>{counter}</h1>
<button onClick={() => setCounter(counter+1)}>+ 버튼</button>
</>
)
}
export default Counter;