diff --git a/package.json b/package.json
index f5e78bf..7207e18 100644
--- a/package.json
+++ b/package.json
@@ -84,6 +84,10 @@
 			{
 				"command": "extension.findLowercaseEnums",
 				"title": "findLowercaseEnums"
+			}, 
+			{
+				"command": "extension.findDuplicateCode",
+				"title": "findDuplicateCode"
 			}
 		],
 		"menus": {
diff --git a/src/extension.ts b/src/extension.ts
index 2814544..a36350c 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -8,6 +8,8 @@ import { findCapitalizedMethodName } from './findCapitalizedMethodName';
 import { singleStatementPerLineChecker } from './singleStatementPerLineChecker';
 import { findAllErrors } from './findAllErrors';
 import { convertMapToJson } from './convertMapToJson';
+import { findDuplicateCode } from './findDuplicateCode';
+
 
 const myMap: Map<number, string[]> = new Map();
 const filePath = "/Users/willscomputer/Desktop/abc/gradeFast-1.0/output/data.json";
@@ -22,6 +24,7 @@ export function activate(context: vscode.ExtensionContext) {
     const disposable2 = vscode.commands.registerCommand('extension.findCapitalizedMethodName', findCapitalizedMethodName);
     const disposable3 = vscode.commands.registerCommand('extension.singleStatementPerLineChecker', singleStatementPerLineChecker);
     const disposable0 = vscode.commands.registerCommand('extension.findAllErrors', findAllErrors);
+    const disposable4 = vscode.commands.registerCommand('extension.findDuplicateCode', findDuplicateCode);
 
     const commentController = vscode.comments.createCommentController('comment-sample', 'Comment API Sample');
     context.subscriptions.push(commentController);
diff --git a/src/findDuplicateCode.ts b/src/findDuplicateCode.ts
new file mode 100644
index 0000000..b4eb95a
--- /dev/null
+++ b/src/findDuplicateCode.ts
@@ -0,0 +1,86 @@
+import * as vscode from 'vscode';
+
+export function findDuplicateCode() {
+    const editor = vscode.window.activeTextEditor;
+    if (editor) {
+        const document = editor.document;
+        const text = document.getText();
+        const lines = text.split('\n');
+        const duplicates: Map<string, number[]> = new Map();
+
+        // Iterate through each line of the document
+        lines.forEach((line, index) => {
+            // Match method signatures
+            const methodNameMatch = line.match(/\b(public|private|protected)?\s+(\w+)\s+(\w+)\s*\(/);
+            if (methodNameMatch && methodNameMatch[3]) {
+                const methodNameLower = methodNameMatch[3].toLowerCase();
+                // Store line number in the map of duplicates
+                if (duplicates.has(methodNameLower)) {
+                    duplicates.get(methodNameLower)!.push(index + 1);
+                } else {
+                    duplicates.set(methodNameLower, [index + 1]);
+                }
+            }
+
+            // Match class/interface declarations
+            const classInterfaceNameMatch = line.match(/\b(class|interface)\s+(\w+)/);
+            if (classInterfaceNameMatch && classInterfaceNameMatch[2]) {
+                const classNameLower = classInterfaceNameMatch[2].toLowerCase();
+                // Store line number in the map of duplicates
+                if (duplicates.has(classNameLower)) {
+                    duplicates.get(classNameLower)!.push(index + 1);
+                } else {
+                    duplicates.set(classNameLower, [index + 1]);
+                }
+            }
+        });
+
+        // Show information message with duplicate lines
+        if (duplicates.size > 0) {
+            let message = 'Duplicate code found on lines: ';
+            // Construct message with duplicate lines
+            duplicates.forEach((lineNumbers, name) => {
+                message += `${name}: `;
+                message += lineNumbers.map(num => num.toString()).join(', ');
+                message += '; ';
+            });
+            message = message.slice(0, -2); // Remove the trailing space and semicolon
+            vscode.window.showInformationMessage(message);
+            // Highlight duplicate lines in the editor
+            highlightLines(editor, duplicates);
+        } else {
+            vscode.window.showInformationMessage('No duplicate code found.');
+        }
+    }
+}
+
+/**
+ * Highlights duplicate lines in the editor.
+ * @param editor The active text editor.
+ * @param duplicates A map containing duplicate lines.
+ */
+function highlightLines(editor: vscode.TextEditor, duplicates: Map<string, number[]>) {
+    const document = editor.document;
+    const decorations: vscode.DecorationOptions[] = [];
+
+    // Iterate through each entry in the map of duplicates
+    duplicates.forEach(lineNumbers => {
+        lineNumbers.forEach(lineNumber => {
+            // Get the line and range corresponding to each duplicate line number
+            const line = document.lineAt(lineNumber - 1);
+            const range = line.range;
+            // Create decoration options for each duplicate line
+            decorations.push({
+                range: range,
+                renderOptions: {
+                    // No decoration options needed
+                }
+            });
+        });
+    });
+
+    // Set decorations in the editor to highlight the duplicate lines
+    editor.setDecorations(vscode.window.createTextEditorDecorationType({
+        backgroundColor: 'rgba(255, 128, 0, 0.3)'
+    }), decorations);
+}