Singly Linked List Practice — JavaScript

Today I practiced implementing a Singly Linked List from scratch using JavaScript.

After understanding the core structure, I challenged myself to implement additional operations rather than simply following an existing implementation.

Implemented Operations

prepend(value) append(value) find(value) delete(value) insertBefore(currentValue, newValue) insertAfter(currentValue, newValue) deleteAt(index) toArray()

Complexity Analysis

prepend() → Time: O(1) | Space: O(1) append() → Time: O(n) | Space: O(1) find() → Time: O(n) | Space: O(1) insertBefore() → Time: O(n) | Space: O(1) insertAfter() → Time: O(n) | Space: O(1) delete() → Time: O(n) | Space: O(1) deleteAt() → Time: O(n) | Space: O(1)

Key Learning

The most important part of this exercise was understanding how node references and next pointers control the structure of a Linked List.

For example, inserting a node doesn't require shifting existing elements like an Array. Instead, we update the relevant references:

Before:

10 → 20 → 40

After inserting 30:

10 → 20 → 30 → 40

This was a great exercise for strengthening my understanding of data structures, traversal, references, and algorithmic thinking.

Next challenge: Reverse a Singly Linked List from scratch.

#JavaScript #DSA #DataStructures #Algorithms #Programming #Learning