Сделали несколько страниц с отложенной загрузкой

package-lock.json

@@ -9,7 +9,8 @@
       "version": "0.0.0",
       "dependencies": {
         "react": "^19.1.0",
-        "react-dom": "^19.1.0"
+        "react-dom": "^19.1.0",
+        "react-router-dom": "^7.17.0"
       },
       "devDependencies": {
         "@eslint/js": "^9.25.0",
@@ -1600,6 +1601,19 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/cookie": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/cookie/-/cookie-1.1.1.tgz",
+      "integrity": "sha512-ei8Aos7ja0weRpFzJnEA9UHJ/7XQmqglbRwnf2ATjcB9Wq874VKH9kfjjirM6UhU2/E5fFYadylyhFldcqSidQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/express"
+      }
+    },
     "node_modules/cross-spawn": {
       "version": "7.0.6",
       "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.6.tgz",
@@ -2471,6 +2485,44 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/react-router": {
+      "version": "7.17.0",
+      "resolved": "https://registry.npmjs.org/react-router/-/react-router-7.17.0.tgz",
+      "integrity": "sha512-FDELK7rTMlCHO5+reyXsPlmfr7N1F91lPHsWYfMEGQm/KQ+F4JFM8jGoeQDmDvdTs93Fw9aSilH+uKRb4/jXvQ==",
+      "license": "MIT",
+      "dependencies": {
+        "cookie": "^1.0.1",
+        "set-cookie-parser": "^2.6.0"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=18",
+        "react-dom": ">=18"
+      },
+      "peerDependenciesMeta": {
+        "react-dom": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/react-router-dom": {
+      "version": "7.17.0",
+      "resolved": "https://registry.npmjs.org/react-router-dom/-/react-router-dom-7.17.0.tgz",
+      "integrity": "sha512-fyU2yjGups/hE6Xz0I5ZYbVL8Gx29eCjgpHaRaTaVU+OOAdfRX05KsvyRm0GO8YQwOkhpU3MurW1jyMUJn+zSw==",
+      "license": "MIT",
+      "dependencies": {
+        "react-router": "7.17.0"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=18",
+        "react-dom": ">=18"
+      }
+    },
     "node_modules/resolve-from": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/resolve-from/-/resolve-from-4.0.0.tgz",
@@ -2544,6 +2596,12 @@
         "semver": "bin/semver.js"
       }
     },
+    "node_modules/set-cookie-parser": {
+      "version": "2.7.2",
+      "resolved": "https://registry.npmjs.org/set-cookie-parser/-/set-cookie-parser-2.7.2.tgz",
+      "integrity": "sha512-oeM1lpU/UvhTxw+g3cIfxXHyJRc/uidd3yK1P242gzHds0udQBYzs3y8j4gCCW+ZJ7ad0yctld8RYO+bdurlvw==",
+      "license": "MIT"
+    },
     "node_modules/shebang-command": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/shebang-command/-/shebang-command-2.0.0.tgz",

package.json

@@ -4,14 +4,15 @@
   "version": "0.0.0",
   "type": "module",
   "scripts": {
-    "dev": "vite", 
+    "dev": "vite",
     "build": "vite build",
     "lint": "eslint .",
     "preview": "vite preview"
   },
   "dependencies": {
     "react": "^19.1.0",
-    "react-dom": "^19.1.0"
+    "react-dom": "^19.1.0",
+    "react-router-dom": "^7.17.0"
   },
   "devDependencies": {
     "@eslint/js": "^9.25.0",

src/App.jsx

@@ -1,83 +1,28 @@
-import memo, { useMemo, useCallback, useState } from 'react'
+import { Suspense, lazy } from 'react'
+import { BrowserRouter, Routes, Route } from 'react-router-dom'
 
-function MyComponent() {
-    const [count, setCount] = useState(0);
-    const [name, setName] = useState('John');
-    
-    const greeting = useMemo(() => `Hello, ${name}!`,[name]);
-    
-    return (
-        <>
-        <h2>{greeting}</h2>
-        <button onClick={()=>setName('Alex')}>New name</button>
-        </>
-    )
-}
-
-function MyComponent2() {
-    const [data,setData] = useState([{theme:'light'}])
-    const userPreferences = useMemo(()=>({theme: 'dark', language: 'en'}),[]);
-    
-    const processData = useMemo(()=>{
-        return data.map(item => ({ ...item,theme: userPreferences.theme }))
-    },[data, userPreferences]);
-    console.log(processData);
-    return (
-        <>
-            <h2 className={data.theme}>2</h2>
-            <button onClick={()=>setData(data)}>set new theme</button>
-        </>
-    )
-}
-
-function MyComponent3() {
-    const sum = useMemo(()=> a+b,[a,b]);//Бессмысленное применение и вредное
-
-    //Применение оправдано
-    const complexResult = useMemo(()=>{
-        return heavyMethOperations(largeDataSet);
-    },[largeDataSet])
-}
-
-function ParentComponent({ items }) {
-    const [filter, setFilter] = useState('');
-    
-    const listProps = useMemo(()=>({
-            items: items.filter(item => item.name.includes(filter)),
-            onItemClick: id => console.log('Clicked',id),
-            theme: 'dark'
-        }),[items,filter]);
-    
-    return (
-        <>
-        <Memoized {...listProps} />
-        <button onClick={()=>setFilter('Bob')}>Click</button>
-        </>
-    )
-}
-
-function Memoized(props) {
-    console.log(props);
-    return (
-        <>
-        <h3 className={props.theme}>Memoized</h3>
-        {props.items.map((item) => (
-         <>
-            <li>
-                {item.name}
-            </li>
-         </>))}
-        </>
-    )
-}
+const HomePage = lazy(() => import('./pages/HomePage'))
+const AboutPage = lazy(() => import('./pages/AboutPage'))
+const ContactPage = lazy(() => import('./pages/ContactPage'))
+const AdminPanel = lazy(() => import('./pages/AdminPanel'))
 
 function App() {
 	return (
-		<>
-			{/* Добавьте тестовый контент для проверки */}
-			<h1>Hello, React!</h1>
-            <ParentComponent items={[{name:'Alex'},{name:'Bob'}]} />
-		</>
+		<BrowserRouter>
+		    <div>
+                <nav><a href='/'>Главная</a> <a href='/about'>О нас</a> <a href='/contact'>Контакты</a></nav>
+                <main>
+                    <Suspense fallback={<div>Загрузка ...</div>}>
+                        <Routes>
+                            <Route path='/' element={<HomePage />} />
+                            <Route path='/about' element={<AboutPage />} />
+                            <Route path='/contact' element={<ContactPage />} />
+                            <Route path='/admin' element={<AdminPanel />} />
+                        </Routes>
+                    </Suspense>
+                </main>
+		    </div>
+		</BrowserRouter>
 	)
 }
 

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>
 )

src/pages/AboutPage.jsx

@@ -0,0 +1,9 @@
+export function MyComponent() {
+    return (
+        <>
+        <h1>About Page</h1>
+        </>
+        )
+}
+
+export default MyComponent

src/pages/AdminPanel.jsx

@@ -0,0 +1,9 @@
+export function MyComponent() {
+    return (
+        <>
+        <h1>Admin Page</h1>
+        </>
+        )
+}
+
+export default MyComponent

src/pages/ContactPage.jsx

@@ -0,0 +1,9 @@
+export function MyComponent() {
+    return (
+        <>
+        <h1>Contact Page</h1>
+        </>
+        )
+}
+
+export default MyComponent

src/pages/HomePage.jsx

@@ -0,0 +1,9 @@
+export function MyComponent() {
+    return (
+        <>
+        <h1>Home Page</h1>
+        </>
+        )
+}
+
+export default MyComponent