Сделали useReducer для счетчика

src/App.jsx

@@ -1,44 +1,50 @@
-import React from 'react'
+import { useState, useReducer } from 'react'
 
-class Clock extends React.Component {
+function counterReducer(state, action) {
-    constructor(props) {
+    switch (action.type) {
-        super(props)
+        case 'increment':
-        this.state = { time: new Date().toLocaleTimeString() }
+            return state + 1
+        case 'decrement':
+            return state - 1
+        case 'reset':
+            return 0
+        case 'set_value':
+            return action.value
+        default:
+            return state
+    }
 }
 
-    componentDidMount() {
+function Counter() {
-        this.timerId = setInterval(()=>{
+    const [count, dispatch] = useReducer(counterReducer,0);
-            this.setState({ time: new Date().toLocaleTimeString() })
-        }, 1000);
-        console.log('Таймер смонтирован')
-    }
     
-    componentDidUpdate(prevProps,prevState) {
+    return (
-        console.log('Компонент обнвлен')
+        <div>
-    }
+            <span>Счетчик: {count}</span>
-    
+            <button onClick={()=> dispatch({type: 'increment'})}>+</button>
-    componentWillUnmount() {
+            <button onClick={()=> dispatch({type: 'decrement'})}>-</button>
-        clearInterval(this.timerId)
+            <button onClick={()=> dispatch({type: 'reset'})}>reset</button>
-        console.log('Компонент таймера размонтирован')
+            <button onClick={()=> dispatch({type: 'set_value', value: 5})}>set 5</button>
-    }
-    
-    render() {
-        return <div>
-            <h2>Текущее время: {this.state.time}</h2>
         </div>
-    }
+    )
 }
 
 function App() {
-    const [showClock, setShowClock] = React.useState(true);
+    const [tasks, setTasks] = useState([])
+    const [filter, setFilter] = useState('all')
+    const [sortBy,setSortBy] = useState('date')
+    
+    const addTask = newTask => {
+        setTasks([...tasks,newTask])
+    }
+    
+    
     
 	return (
 		<>
-			<h1>Жизненный цикл компонента часов</h1>
+			{/* Добавьте тестовый контент для проверки */}
-            <button onClick={()=> setShowClock(!showClock)}>
+			<h1>Hello, React!</h1>
-                {showClock ? 'Скрыть часы' : 'Показать часы' }
+            <Counter />
-            </button>
-            {showClock && <Clock />}
 		</>
 	)
 }

src/App.module.scss

@@ -0,0 +1,15 @@
+.container {
+/*    display: flex;
+    flex-direction: column;
+    flex-wrap: nowrap;*/
+    height: 500px;
+    overflow: auto;
+    border: 1px solid black;
+}
+.item {
+    font-size: 16pt;
+    border: 1px dotted gray;
+    /*margin: 5px 10px;
+    padding: 10px;*/
+    border-radius: 5px;
+}

src/main.jsx

@@ -4,5 +4,7 @@ import { createRoot } from 'react-dom/client'
 import App from './App.jsx'
 
 createRoot(document.getElementById('root')).render(
+	<StrictMode>
 		<App />
+	</StrictMode>
 )