Linked Lists

This lesson covers linked lists — a fundamental dynamic data structure where elements are stored in nodes connected by pointers. Linked lists are a key topic in A-Level Computer Science and provide the foundation for understanding many other data structures.

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What is a Linked List?

A linked list is a dynamic data structure consisting of a sequence of nodes. Each node contains:

1. Data — the value stored in the node.
2. Pointer (next) — a reference to the next node in the list.

The first node is called the head. The last node's pointer is set to null (or None), indicating the end of the list.

HEAD → [Data|Next] → [Data|Next] → [Data|Next] → NULL

Example

HEAD → [10|●] → [20|●] → [30|●] → NULL

This linked list contains three nodes storing the values 10, 20, and 30.

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Types of Linked Lists