Steps of Working of LinkedList:

• Below are the steps of working of LinkedList in Java:
  1. Creation of LinkedList:
     • A new LinkedList can be created using:
       LinkedList<String> list = new LinkedList<>();
     • Initially, the LinkedList is empty — it has no nodes. The head and tail both point to null.
     • Internal structure at the beginning: Head → null, Tail → null, Size = 0
  2. Adding the First Element:
     • When we add the first element using add():
       list.add("A");
     • A new Node is created that contains:
       • Data → "A"
       • Previous → null
       • Next → null
       • Size → 0
     • Both head and tail point to this single node.
       
  3. Adding More Elements:
     • When we add more elements, new nodes are created and connected sequentially.
       list.add("B");
list.add("C");
list.add("D");
     • Each new node is linked at the end of the list:
       
     • The Previous pointer of each node points to the previous element, and the Next pointer points to the next element — making it a Doubly Linked List.
  4. Adding or Deleting Elements in the Middle:
     • When inserting or deleting (removing) elements in the middle, the surrounding nodes’ pointers are adjusted.
     • Example – inserting "X" between "B" and "C":
       
     • The Previous and Next references of neighboring nodes are updated accordingly.
  5. Traversal of LinkedList:
     • The LinkedList is traversed sequentially from head to tail using Iterator or ListIterator.
     • Example:

       Iterator<String> itr = list.iterator();
       while (itr.hasNext())
       {
           System.out.println(itr.next());
       }

     • Unlike ArrayList, elements are not accessed using indexes directly; instead, traversal follows node links.

LinkedList is Good for:

1. Insertion and Deletion at the beginning, middle or end:
   • Each element (called a node) contains a reference to the previous and next node.
   • Insertion and deletion only involve changing the links, not shifting elements like in ArrayList.
2. Frequent modifications (add/remove):
   • Performs efficiently when elements are frequently added or removed from different positions.
3. Memory management of variable-size data:
   • Each node is allocated separately in memory, allowing dynamic growth without resizing.

LinkedList is Not Good for:

1. Accessing elements by index (get(int index)):
   • Slow because traversal starts from the head or tail node to reach the given index (no direct access).
2. Memory overhead:
   • Each node stores extra references (next and prev), consuming more memory.
3. Poor cache locality:
   • Nodes are scattered in memory (non-contiguous), resulting in slower iteration compared to ArrayList.
4. Random access operations:
   • Since nodes are connected by references, random access takes O(n) time.

Summary Table: