useReducer example from React Hooks

UseReducerComponent.js

import React, { useReducer } from "react";

function reducer(state, action) {
  switch (action) {
    case "add":
      return { count: state.count + 1 };
    case "sub":
      return { count: state.count - 1 };
    default:
      return state;
  }
}

function UseReducerComponent() {
  const [state, dispatch] = useReducer(reducer, { count: 0 });
  return (
    <div>
      <p>Count: {state.count}</p>
      <button onClick={() => dispatch("add")}>Add</button>
      <button onClick={() => dispatch("sub")}>Sub</button>
    </div>
  );
}

export default UseReducerComponent;