Сделали React.memo и React.useMemo

package.json

@@ -10,7 +10,6 @@
     "preview": "vite preview"
   },
   "dependencies": {
-    "info": "^1.0.0",
     "react": "^19.1.0",
     "react-dom": "^19.1.0"
   },
@@ -23,8 +22,6 @@
     "eslint-plugin-react-hooks": "^5.2.0",
     "eslint-plugin-react-refresh": "^0.4.19",
     "globals": "^16.0.0",
-    "sass": "^1.99.0",
-    "sass-embedded": "^1.99.0",
     "vite": "^6.3.5"
   }
 }

src/App.jsx

@@ -1,30 +1,60 @@
-import styles from './styles/App.module.scss'
+import { memo, useState, useMemo } from 'react'
-import React, { useState, useCallback } from 'react'
 
-function CounterButton({label, onClick}) {
+function memoize(fn) {
-    return (
+    const cache = new Map();
-        <button onClick={onClick} className={styles.counter_button}>{label}</button>
+    return function(...args) {
-    )
+        const key = JSON.stringify(args);
+        if (cache.has(key)) {
+            return cache.get(key);
+        }
+        const result = fn.apply(this, args);
+        cache.set(key,result);
+        return result;
+    }
 }
-function CounterDisplay({value}) {
+
-    return (<div className={styles.counter_display}>
+function fibonachi(n, memo={}) {
-            Значение счетчика: <b>{value}</b>
+    if (n in memo) {console.log(n);return memo[n];}
-    </div>)
+    if (n <= 1) return 1;
+    memo[n] = fibonachi(n-1, memo) + fibonachi(n - 2, memo);
+    return memo[n];
+}
+
+const MyComponent = ({ value }) => {
+    console.log('Rendring');
+    return <div>{value}</div>
+}
+
+const MemoizedComponent = memo(MyComponent);
+
+const Child = memo(({ children }) => {
+    console.log('Child component rendred');
+    return <div>{children}</div>;
+});
+
+const Parent = () => {
+    const [count,setCount] = useState(0);
+    const [text, setText] = useState('');
+    
+    const stableChild = useMemo(() => <span>Memo text</span>,[]);
+    
+    return (
+        <>
+            <Child>
+                {stableChild}
+            </Child>
+            <input type="text" onChange={(e) => setText(e.target.value)} value={text} />
+            <button onClick={() => setCount(count + 1)}>Increment {count}</button>
+        </>
+    )
 }
 
 function App() {
-    const [counter,setCounter] = useState(0);
-    
-    const increment = () => setCounter(prev => prev + 1);
-    const decrement = () => setCounter(prev => prev - 1);
-    
 	return (
 		<>
-            <h2>Практика по созданию счетчика с колбэками</h2>
+			<h1>Hello, React!</h1>
-            <CounterButton label="Увеличить" onClick={increment} />
+            <Parent />
-            <CounterButton label="уменьшить" onClick={decrement} />
+        </>
-            <CounterDisplay value={counter} />
-		</>
 	)
 }
 

src/main.jsx

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