LinkedList usage in C Sharp (C#) - Step-by-Step Execution

Concept Flow - LinkedList usage

Create LinkedList object

↓

Add nodes (AddFirst/AddLast)

↓

Traverse nodes from Head

↓

Access or modify node values

↓

Remove nodes (Remove/RemoveFirst/RemoveLast)

↓

Check if list is empty or contains value

↓

End of operations

This flow shows how to create a linked list, add nodes, traverse them, modify or remove nodes, and check list properties.

Execution Sample

C Sharp (C#)

var list = new LinkedList<int>();
list.AddLast(10);
list.AddFirst(5);
list.AddLast(15);
foreach(var val in list) Console.Write(val + " ");

Creates a linked list, adds three numbers, then prints them in order.

Execution Table

Step	Operation	LinkedList Nodes	Pointer Changes	Visual State
1	Create LinkedList<int> list	empty	head=null, tail=null	[]
2	AddLast(10)	10	head=Node(10), tail=Node(10)	[10]
3	AddFirst(5)	5 -> 10	head=Node(5), tail=Node(10)	[5 -> 10]
4	AddLast(15)	5 -> 10 -> 15	tail=Node(15)	[5 -> 10 -> 15]
5	Traverse and print	5 -> 10 -> 15	head=Node(5)	Output: '5 10 15 '
6	End	5 -> 10 -> 15	no change	Traversal complete

💡 Traversal ends after last node (Node with 15) is processed.

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	After Step 5	Final
list.Count	0	1	2	3	3	3
list.Head.Value	null	10	5	5	5	5
list.Tail.Value	null	10	10	15	15	15

Key Moments - 3 Insights

Why does AddFirst(5) put 5 before 10 in the list?

AddFirst inserts a new node at the start, so the new node becomes the head, pushing existing nodes after it. See execution_table step 3 where head changes to Node(5).

How does the list keep track of the last node after AddLast(15)?

AddLast updates the tail pointer to the new node. The previous tail's next pointer links to the new node. See execution_table step 4 where tail changes to Node(15).

What happens during traversal in the foreach loop?

Traversal starts at head and moves through each node's next pointer until the end (null). Output is generated in order. See execution_table step 5.

Visual Quiz - 3 Questions

Look at the execution_table at step 3, what is the head node's value?

A 15

B 5

C 10

D null

💡 Hint

Check the 'Pointer Changes' and 'LinkedList Nodes' columns at step 3.

At which step does the list contain three nodes?

A Step 2

B Step 3

C Step 4

D Step 5

💡 Hint

Look at the 'LinkedList Nodes' column and 'list.Count' in variable_tracker.

If we remove the first node after step 4, what would be the new head value?

A 10

B 5

C 15

D null

💡 Hint

Removing the first node moves head to the next node. See how AddFirst and AddLast set head and tail.

Concept Snapshot

LinkedList usage in C#:
- Create with LinkedList<T> list = new LinkedList<T>();
- Add nodes: AddFirst(value), AddLast(value)
- Traverse with foreach(var item in list)
- Remove nodes: Remove(value), RemoveFirst(), RemoveLast()
- Head and Tail track start/end nodes
- Count gives number of nodes

Full Transcript

This example shows how to use a LinkedList in C#. First, we create an empty list. Then we add nodes using AddLast and AddFirst, which update the head and tail pointers accordingly. The list nodes link in order, allowing traversal from head to tail. The foreach loop visits each node in order, printing their values. Key points include how AddFirst inserts at the start, changing the head, and AddLast appends at the end, changing the tail. The variable tracker shows how count and pointers change after each operation. This helps understand the linked list structure and usage.