Collection FrameWork folder added

Author: imharshtiwari

Collection-Framework/ArrayList/DemoArrayList.java

@@ -0,0 +1,99 @@
+
+import java.util.ArrayList;
+
+public class DemoArrayList {
+    public static void main(String[] args) {
+        // Create an ArrayList of integers
+        ArrayList al = new ArrayList();
+
+    //Arraylist <String> al = new ArrayList<String>(); // ArrayList<String> this is generic array
+    // used to defiine type parameters
+
+    //checking whether list is empty or not
+    boolean isEmpty = al.isEmpty();
+    System.out.println("Is the ArrayList empty? " + isEmpty);
+        
+        // Add elements to the ArrayList
+        al.add(10);
+        al.add(20);
+        al.add(20);
+        al.add(20);
+        al.add("hello");
+        al.add(30);
+        al.add("hello");
+        al.add("hello");
+        al.add(50.20);
+        al.add("hello world");
+    
+
+        
+        // Print the ArrayList
+        System.out.println("ArrayList: " + al);
+        
+        // Get the size of the ArrayList
+        int size = al.size();
+        System.out.println("Size of the ArrayList: " + size);
+        
+        
+        // Get the element at a specific index
+        Object element = al.get(2);
+        System.out.println("Element at index 2: " + element);
+        
+        // Remove an element from the ArrayList
+        al.remove(2);
+        System.out.println("Updated ArrayList: " + al);
+
+
+        System.out.println("Before update" + al);
+        //Set an element at a specific index
+        al.set(1, "Adding at 01 index");
+        System.out.println("Updated ArrayList: " + al);
+        
+        
+        // Check if an element exists in the ArrayList
+        boolean exists = al.contains(30);
+        System.out.println("Element 30 exists in the ArrayList: " + exists);
+        //or
+       // System.out.println(al.contains("hello"));
+        
+
+        
+    
+        
+        // Clear the ArrayList
+       // al.clear();
+       // System.out.println("After clearing the ArrayList: " + al);
+
+        // retain all the elements
+        al.retainAll(al);
+        System.out.println("After retain " + al);
+
+        //trnasversing arrays
+        System.out.println("Before traversal: " + al);
+        for (Object obj : al) {      //traversing   using for each element in the array 
+            System.out.println(obj);
+        }
+        System.out.println("After traversal: " + al);
+         
+       for(int i = 0; i<al.size(); i++){   //using for loop  
+           System.out.println(al.get(i));
+        }
+
+                 
+
+
+    }
+
+    
+    // Add more methods here to perform other operations on the ArrayList
+    // For example, finding the maximum or minimum element, sorting the ArrayList, etc.
+    // Feel free to add as many methods as you want!
+    }
+    // Note: The ArrayList provided here is a generic ArrayList, meaning it can store elements of any type.
+    // If you want to store elements of a specific type, you can use a different type of ArrayList, such as ArrayList<String> for storing strings.
+    // You can also use custom objects as elements by implementing the Comparable interface in your custom class.
+    // For example, if you have a class called "Person" with a name and age, you can create an ArrayList<Person> to store Person objects.
+    // If you need more advanced features or need to store custom objects, you may want to consider using a different data structure or library, such as Java's Collections Framework or Apache Commons Collections.
+    // Also, remember to handle any potential exceptions that may occur when using the ArrayList, such as IndexOutOfBoundsException or NullPointerException.
+    
+