text: import React, { useReducer } from 'react';
  
  function reducer(state, action) {
    switch (action.type) {
      case 'INCREMENT':
        return state + 1;
      case 'DECREMENT':
        return state - 1;
      default:
        throw new Error('Unhandled action');
    }
  }
  
  function Counter() {
  
    const [number, dispatch] = useReducer(reducer, 0);
  
    const onIncrease = () => {
      dispatch({
        type: 'INCREMENT'
      })
    };
  
    const onDecrease = () => {
      dispatch({
        type: 'DECREMENT'
      })
    };
  
    return (
      <div>
        <h1>{number}</h1>
        <button onClick={onIncrease}>+1</button>
        <button onClick={onDecrease}>-1</button>
      </div>
    )
  }
  
  export default Counter;