diff --git a/OOP/Java/Lab/Week12/DiffTypeGeneric.java b/OOP/Java/Lab/Week12/DiffTypeGeneric.java
new file mode 100644
index 0000000..f060f3f
--- /dev/null
+++ b/OOP/Java/Lab/Week12/DiffTypeGeneric.java
@@ -0,0 +1,24 @@
+public class DiffTypeGeneric {
+
+    public static <T> void printArray(T[] array) {
+        for (T element : array) {
+            System.out.print(element + " ");
+        }
+        System.out.println();
+    }
+
+    public static void main(String[] args) {
+        Integer[] intArray = { 1, 2, 3, 4, 5 };
+        Double[] doubleArray = { 1.1, 2.2, 3.3, 4.4, 5.5 };
+        String[] stringArray = { "Hello", "World", "Generic", "Method" };
+
+        System.out.println("Integer Array:");
+        printArray(intArray);
+
+        System.out.println("Double Array:");
+        printArray(doubleArray);
+
+        System.out.println("String Array:");
+        printArray(stringArray);
+    }
+}
diff --git a/OOP/Java/Lab/Week12/GenList.java b/OOP/Java/Lab/Week12/GenList.java
new file mode 100644
index 0000000..7148734
--- /dev/null
+++ b/OOP/Java/Lab/Week12/GenList.java
@@ -0,0 +1,66 @@
+public class SinglyLinkedListDemo {
+
+    public static void main(String[] args) {
+        // Test with Integer
+        SinglyLinkedList<Integer> intList = new SinglyLinkedList<>();
+        intList.add(10);
+        intList.add(20);
+        intList.add(30);
+
+        System.out.println("Integer List:");
+        intList.printList();
+
+        // Test with Double
+        SinglyLinkedList<Double> doubleList = new SinglyLinkedList<>();
+        doubleList.add(1.1);
+        doubleList.add(2.2);
+        doubleList.add(3.3);
+
+        System.out.println("\nDouble List:");
+        doubleList.printList();
+    }
+}
+
+class SinglyLinkedList<T> {
+
+    private class Node {
+
+        T data;
+        Node next;
+
+        Node(T data) {
+            this.data = data;
+            this.next = null;
+        }
+    }
+
+    private Node head;
+
+    public SinglyLinkedList() {
+        head = null;
+    }
+
+    public void add(T data) {
+        Node newNode = new Node(data);
+
+        if (head == null) {
+            head = newNode;
+            return;
+        }
+
+        Node current = head;
+        while (current.next != null) {
+            current = current.next;
+        }
+        current.next = newNode;
+    }
+
+    public void printList() {
+        Node current = head;
+        while (current != null) {
+            System.out.print(current.data + " -> ");
+            current = current.next;
+        }
+        System.out.println("null");
+    }
+}
diff --git a/OOP/Java/Lab/Week12/GenStack.java b/OOP/Java/Lab/Week12/GenStack.java
new file mode 100644
index 0000000..83c2819
--- /dev/null
+++ b/OOP/Java/Lab/Week12/GenStack.java
@@ -0,0 +1,82 @@
+// Generic Stack class
+class Stack<T> {
+
+    private Object[] elements;
+    private int top;
+    private static final int DEFAULT_SIZE = 10;
+
+    public Stack() {
+        elements = new Object[DEFAULT_SIZE];
+        top = -1;
+    }
+
+    public void push(T item) {
+        elements[++top] = item;
+    }
+
+    public T pop() {
+        if (isEmpty()) return null;
+        return (T) elements[top--];
+    }
+
+    public boolean isEmpty() {
+        return top == -1;
+    }
+}
+
+// Student class
+class Student {
+
+    private String name;
+    private int id;
+
+    public Student(String name, int id) {
+        this.name = name;
+        this.id = id;
+    }
+
+    public String toString() {
+        return "Student [name=" + name + ", id=" + id + "]";
+    }
+}
+
+// Employee class
+class Employee {
+
+    private String name;
+    private String department;
+
+    public Employee(String name, String department) {
+        this.name = name;
+        this.department = department;
+    }
+
+    public String toString() {
+        return "Employee [name=" + name + ", department=" + department + "]";
+    }
+}
+
+public class Main {
+
+    public static void main(String[] args) {
+        // Stack of Students
+        Stack<Student> studentStack = new Stack<>();
+        studentStack.push(new Student("John", 101));
+        studentStack.push(new Student("Mary", 102));
+
+        System.out.println("Students popped from stack:");
+        while (!studentStack.isEmpty()) {
+            System.out.println(studentStack.pop());
+        }
+
+        // Stack of Employees
+        Stack<Employee> employeeStack = new Stack<>();
+        employeeStack.push(new Employee("Bob", "IT"));
+        employeeStack.push(new Employee("Alice", "HR"));
+
+        System.out.println("\nEmployees popped from stack:");
+        while (!employeeStack.isEmpty()) {
+            System.out.println(employeeStack.pop());
+        }
+    }
+}
diff --git a/OOP/Java/Lab/Week12/LargestOfThree.java b/OOP/Java/Lab/Week12/LargestOfThree.java
new file mode 100644
index 0000000..8c850ee
--- /dev/null
+++ b/OOP/Java/Lab/Week12/LargestOfThree.java
@@ -0,0 +1,30 @@
+public class LargestOfThree {
+
+    public static <T extends Comparable<T>> T findLargest(T a, T b, T c) {
+        T max = a;
+
+        if (b.compareTo(max) > 0) {
+            max = b;
+        }
+        if (c.compareTo(max) > 0) {
+            max = c;
+        }
+        return max;
+    }
+
+    public static void main(String[] args) {
+        Integer a = 10;
+        Integer b = 5;
+        Integer c = 15;
+
+        System.out.println("The largest number is: " + findLargest(a, b, c));
+
+        String str1 = "apple";
+        String str2 = "orange";
+        String str3 = "banana";
+
+        System.out.println(
+            "The largest string is: " + findLargest(str1, str2, str3)
+        );
+    }
+}
diff --git a/OOP/Java/Lab/Week12/WildCard.java b/OOP/Java/Lab/Week12/WildCard.java
new file mode 100644
index 0000000..67dc55f
--- /dev/null
+++ b/OOP/Java/Lab/Week12/WildCard.java
@@ -0,0 +1,24 @@
+class Wildcard {
+
+    static void printArray(Object[] elements) {
+        for (Object element : elements) {
+            System.out.print(element + " ");
+        }
+        System.out.println();
+    }
+
+    public static void main(String[] args) {
+        Integer[] intArray = { 1, 2, 3, 4, 5 };
+        String[] stringArray = { "Hello", "World" };
+        Double[] doubleArray = { 1.1, 2.2, 3.3 };
+
+        System.out.println("Integer Array:");
+        printArray(intArray);
+
+        System.out.println("String Array:");
+        printArray(stringArray);
+
+        System.out.println("Double Array:");
+        printArray(doubleArray);
+    }
+}