added code split

client/src/pages/Notes/ReactPatterns/ReactNotes/CodeSplitting.jsx

@@ -0,0 +1,161 @@
+import React from "react";
+import CodeBlock from "../../components/CodeBlock";
+
+const CodeSplitting = () => {
+  const examples = [
+    {
+      title: "Basic Code Splitting with React.lazy",
+      code: `import React, { Suspense, lazy } from "react";
+
+const LazyComponent = lazy(() => import("./LazyComponent"));
+
+function App() {
+  return (
+    <Suspense fallback={<div>Loading...</div>}>
+      <LazyComponent />
+    </Suspense>
+  );
+}
+
+export default App;`,
+      explanation:
+        "React allows splitting your code into smaller bundles that load on demand. This reduces the initial load time and improves performance for large apps.",
+    },
+    {
+      title: "Route-based Code Splitting",
+      code: `import React, { Suspense, lazy } from "react";
+import { BrowserRouter as Router, Route, Routes } from "react-router-dom";
+
+const Home = lazy(() => import("./Home"));
+const About = lazy(() => import("./About"));
+
+function App() {
+  return (
+    <Router>
+      <Suspense fallback={<div>Loading...</div>}>
+        <Routes>
+          <Route path="/" element={<Home />} />
+          <Route path="/about" element={<About />} />
+        </Routes>
+      </Suspense>
+    </Router>
+  );
+}
+
+export default App;`,
+      explanation:
+        "Code splitting can be applied per route, allowing only the components for the active route to be loaded initially. This improves page load performance.",
+    },
+  ];
+
+  const bestPractices = [
+    "Use code splitting for large components or pages.",
+    "Combine with React Suspense to show fallback UI during loading.",
+    "Prefer route-based splitting for multi-page applications.",
+    "Avoid splitting very small components as it may increase bundle overhead.",
+    "Monitor network requests to ensure chunks are loaded efficiently.",
+  ];
+
+  const commonMistakes = [
+    "Not using Suspense fallback, causing blank UI during loading.",
+    "Splitting too many tiny components, increasing HTTP requests.",
+    "Assuming code splitting automatically improves all performance issues.",
+    "Ignoring error handling for lazy-loaded components.",
+  ];
+
+  return (
+    <div className="max-w-7xl mx-auto">
+      <h1 className="text-3xl font-bold text-gray-800 dark:text-white mb-6">
+        React{" "}
+        <span className="text-primary-600 dark:text-primary-400">
+          Code Splitting
+        </span>
+      </h1>
+
+      <div className="prose max-w-none">
+        <p className="text-base text-gray-700 dark:text-gray-300 mb-6 leading-relaxed">
+          <strong>Code splitting</strong> in React allows you to split your
+          app into smaller chunks that can be loaded on demand. This helps
+          improve the initial load time and performance of your application,
+          especially for large apps.
+        </p>
+
+        <div className="mb-4 bg-white dark:bg-black p-4 rounded-md shadow-sm border border-gray-200 dark:border-gray-700 hover:border-primary-300 dark:hover:border-gray-600 transition-colors">
+          <p className="text-primary-500 dark:text-primary-400">
+            <strong className="font-semibold">Tip:</strong> Use code splitting
+            wisely to load heavy components only when needed, reducing the
+            bundle size for initial load.
+          </p>
+        </div>
+
+        {/* Examples Section */}
+        <section className="mb-8">
+          <h2 className="text-2xl font-semibold text-gray-800 dark:text-white mb-4">
+            Examples
+          </h2>
+          <div className="space-y-6">
+            {examples.map((ex, i) => (
+              <div
+                key={i}
+                className="bg-white dark:bg-black p-6 rounded-md shadow-sm border border-gray-200 dark:border-gray-700 hover:border-primary-300 dark:hover:border-gray-600 transition-colors"
+              >
+                <h3 className="text-lg font-semibold text-primary-600 mb-2">
+                  {ex.title}
+                </h3>
+                <div className="w-full overflow-x-auto">
+                  <CodeBlock code={ex.code} />
+                </div>
+                <p className="text-gray-700 dark:text-gray-300 text-sm mt-2">
+                  {ex.explanation}
+                </p>
+              </div>
+            ))}
+          </div>
+        </section>
+
+        {/* Best Practices */}
+        <section className="mb-8">
+          <h2 className="text-2xl font-semibold text-gray-800 dark:text-white mb-4">
+            Best Practices
+          </h2>
+          <ul className="list-disc pl-6 mb-6 space-y-2 text-gray-700 dark:text-gray-300">
+            {bestPractices.map((practice, index) => (
+              <li key={`best-${index}`} className="text-sm">
+                {practice}
+              </li>
+            ))}
+          </ul>
+        </section>
+
+        {/* Common Mistakes */}
+        <section className="mb-8">
+          <h2 className="text-2xl font-semibold text-gray-800 dark:text-white mb-4">
+            Common Mistakes
+          </h2>
+          <ul className="list-disc pl-6 mb-6 space-y-2 text-gray-700 dark:text-gray-300">
+            {commonMistakes.map((mistake, index) => (
+              <li key={`mistake-${index}`} className="text-sm">
+                {mistake}
+              </li>
+            ))}
+          </ul>
+        </section>
+
+        {/* Summary */}
+        <section className="bg-white dark:bg-black p-4 rounded-md shadow-sm border border-gray-200 dark:border-gray-700 hover:border-primary-300 dark:hover:border-gray-600 transition-colors">
+          <h3 className="text-lg font-semibold text-primary-600 mb-2">
+            Summary
+          </h3>
+          <p className="text-gray-700 dark:text-gray-300 text-sm">
+            Code splitting helps break your React app into smaller bundles
+            that load on demand, improving performance and user experience.
+            Combine it with React.lazy and Suspense for clean, efficient,
+            and user-friendly loading behavior.
+          </p>
+        </section>
+      </div>
+    </div>
+  );
+};
+
+export default CodeSplitting;

client/src/pages/Notes/ReactPatterns/ReactSidebarPage.jsx

@@ -34,6 +34,7 @@ import CompoundComp from "./ReactNotes/CompoundComp";
 import Props from "./ReactNotes/Props";
 
 import HOC from "./ReactNotes/HOC";
+import CodeSplitting from "./ReactNotes/CodeSplitting";
 
 import SuspensePattern from "./ReactNotes/SuspensePattern";
 
@@ -121,6 +122,10 @@ const topicComponents = {
 
 
 
+  "What is react" : <ReactIntroduction/>,
+
+
+
 
 
   "Error Boundary Pattern": <ErrorBoundaryPattern />,
@@ -138,7 +143,14 @@ const topicComponents = {
 
 
 
+
+  "Code Splitting": <CodeSplitting />,
+
+
+
+
   "Suspense Pattern": <SuspensePattern />  
+
   // add all other topics here
 
 };