রিয়েক্ট useReducer

import {createRoot} from "react-dom/client";
import React, {useReducer} from "react";

function reducer(count, action) {
  if (action.type === "increment") {
    return count + 1;
  }
  if (action.type === "decrement") {
    return count - 1;
  }
  return count;
}

function App() {
  const [count, dispatch] = useReducer(reducer, 0);

  return (
    <div>
      <button onClick={() => dispatch({type: "decrement"})}>-</button>
      <span>{count}</span>
      <button onClick={() => dispatch({type: "increment"})}>+</button>
    </div>
  );
}

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