Compare commits
8 Commits
| Author | SHA1 | Date | |
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| c168c96820 | |||
| b70fa47bbc | |||
| bd35029fc1 | |||
| 92dc5df96b | |||
| 3d34262203 | |||
| 1bc2e883a1 | |||
| 8a8a17f44d | |||
| 8f46470a26 |
Generated
+1256
-9
File diff suppressed because it is too large
Load Diff
@@ -10,6 +10,7 @@
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"preview": "vite preview"
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"preview": "vite preview"
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},
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},
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"dependencies": {
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"dependencies": {
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"info": "^1.0.0",
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"react": "^19.1.0",
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"react": "^19.1.0",
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"react-dom": "^19.1.0"
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"react-dom": "^19.1.0"
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},
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},
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@@ -22,6 +23,8 @@
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"eslint-plugin-react-hooks": "^5.2.0",
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"eslint-plugin-react-hooks": "^5.2.0",
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"eslint-plugin-react-refresh": "^0.4.19",
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"eslint-plugin-react-refresh": "^0.4.19",
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"globals": "^16.0.0",
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"globals": "^16.0.0",
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"sass": "^1.99.0",
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"sass-embedded": "^1.99.0",
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"vite": "^6.3.5"
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"vite": "^6.3.5"
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}
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}
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}
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}
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+15
-84
@@ -1,98 +1,29 @@
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import { useState, useRef, useEffect } from 'react'
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import styles from './styles/App.module.scss'
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import React, { useState, useCallback } from 'react'
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function Example() {
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function CounterButton({label, onClick}) {
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const myRef = useRef(null);
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const counterRef = useRef(0);
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const [text, setText] = useState('');
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useEffect(() => {
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myRef.current?.focus();
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},[]);
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const handlerFocus = () => {
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if(myRef.current) {
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myRef.current.focus();
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}
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};
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const handlerChange = (event) => {
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setText(event.target.value);
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}
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counterRef.current += 1;
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return <div>
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<input ref={myRef} text="text" /><br />
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Количество рендров: {counterRef.current}<br />
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<input text="text" onChange={handlerChange} value={text} />
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<button onClick={handlerFocus}>Поставить фокус на поле</button>
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</div>
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}
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function ClickCounter() {
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const countRef = useRef(0);
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function handlerClick() {
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countRef.current += 1;
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//alert(`Нажали ${countRef.current} раз.`);
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}
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return <button onClick={handlerClick}>Нажать</button>;
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}
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function TimerComponent() {
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const timerIdRef = useRef(null);
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useEffect(() => {
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timerIdRef.current = setTimeout(() => {
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alert("Прошло 3 секунды");
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}, 3000);
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return () => {
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clearTimeout(timerIdRef.current);
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}
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},[]);
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}
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function PrevValue({ value }) {
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const prevValueRef = useRef();
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useEffect(() => {
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prevValueRef.current = value;
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});
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return (
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return (
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<div>
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<button onClick={onClick} className={styles.counter_button}>{label}</button>
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Текущее значение: {value} <br />
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Предыдущее значение: {prevValueRef.current}
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</div>
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)
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)
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}
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}
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function CounterDisplay({value}) {
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function ScrollList() {
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return (<div className={styles.counter_display}>
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const listRef = useRef(null);
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Значение счетчика: <b>{value}</b>
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</div>)
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const scrollToBottom = () => {
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if(listRef.current) {
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listRef.current.scrollTop = listRef.current.scrollHeight;
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}
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}
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return (
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<>
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<div ref={listRef}
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style={{height: 200, overflowY: 'auto', border: '1px solid black'}}>
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{[...Array(20)].map((_,i)=>(
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<div key={i}>Элемент № {i + 1}</div>
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))}
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</div>
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<button onClick={scrollToBottom}>Прокрутить вниз</button>
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</>
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)
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}
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}
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function App() {
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function App() {
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const [counter,setCounter] = useState(0);
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const increment = () => setCounter(prev => prev + 1);
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const decrement = () => setCounter(prev => prev - 1);
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return (
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return (
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<>
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<>
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<h1>Hello, React!</h1>
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<h2>Практика по созданию счетчика с колбэками</h2>
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<ScrollList />
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<CounterButton label="Увеличить" onClick={increment} />
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<CounterButton label="уменьшить" onClick={decrement} />
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<CounterDisplay value={counter} />
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</>
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</>
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)
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)
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}
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}
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+3
-1
@@ -1,8 +1,10 @@
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import { StrictMode } from 'react'
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import { StrictMode } from 'react'
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import { createRoot } from 'react-dom/client'
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import { createRoot } from 'react-dom/client'
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// удаляем import './index.css'
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import App from './App.jsx'
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import App from './App.jsx'
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createRoot(document.getElementById('root')).render(
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createRoot(document.getElementById('root')).render(
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<StrictMode>
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<App />
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<App />
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</StrictMode>
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)
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)
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@@ -0,0 +1,22 @@
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.container {
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display:flex;
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flex-direction: row;
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border: 1px solid black;
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border-radius: 5px;
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margin-bottom: 10px;
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p {
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padding: 5px 10px;
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}
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}
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.counter {
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&_display{
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border: 1px solid black;
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border-width: 3px;
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border-radius: 10px;
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padding: 10px;
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width: 300px;
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}
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&_button{
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padding: 10px;
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}
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}
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Reference in New Issue
Block a user