useState snippet

useState.js

import React, { useState } from "react";
import ReactDOM from "react-dom";
// import "./App.css";

class ClassExample extends React.Component {
  constructor(props) {
    super(props);
    this.state = { count: 0 };
  }

  render() {
    return (
      <div>
        <p>You clicked {this.state.count} times</p>
        <button onClick={() => this.setState({ count: this.state.count + 1 })}>
          Click me!
        </button>
      </div>
    );
  }
}

function Example(props) {
  const [count, setCount] = useState(0);
  const [arrst, setArr] = useState({ count: 4 });

  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>Click me!</button>

      <p>You clicked (arr) {arrst.count} times</p>
      <button
        onClick={() => {
          const newObj = { count: arrst.count + 1 };
          setArr(newObj);
        }}
      >
        Click me dict!
      </button>
    </div>
  );
}

function App() {
  return (
    <div>
      <h1>test!</h1>
      <ClassExample />
      <Example />
    </div>
  );
}

ReactDOM.render(<App />, document.getElementById("root"));