Linked Lists in Memory
When we work with arrays, all elements are stored next to each other in memory.
But Linked Lists work differently — each node can be stored anywhere in memory, and they’re connected through pointers.
This makes linked lists flexible and dynamic, as we don’t need to know the size beforehand.
📦 How It Works
A Linked List is made up of nodes, where each node has two parts:
- Data – stores the actual value.
- Pointer (Next) – stores the address (link) of the next node in the list.
| Data | Next | → | Data | Next | → | Data | NULL |
Even though nodes may be scattered throughout memory,
the pointers keep them connected in the correct order.
Linked Lists in Memory
This visualizer shows how linked list nodes are stored at different memory addresses and connected via pointers.
How Linked Lists Are Stored in Memory
Each node in a linked list contains:
- Address: where the node is stored in memory.
- Data: the value held by the node.
- Next: a pointer to the next node’s address.
Unlike arrays, linked list nodes are stored at random memory locations. The Next pointer connects them, forming a chain. The last node points to null, indicating the end of the list.
🧩 Example in Memory
Let’s say we have this list:
[10] → [20] → [30] → NULL
In memory, it might look like this:
Address: 1000 2048 3060
Node: [10|2048] [20|3060] [30|NULL]
Each node stores:
- A data value (like 10, 20, 30)
- A pointer to the next node’s address
So even though they’re not sequentially placed in memory,
the Next pointers maintain the correct sequence.
🧭 Why It Matters
- Dynamic Size: Can easily grow or shrink at runtime.
- No Wasted Space: Doesn’t need contiguous memory like arrays.
- Efficient Insert/Delete: We just adjust the pointers — no shifting of elements.
🧩 In Code (Python Example)
class Node:
def __init__(self, data):
self.data = data
self.next = None
# Create nodes
node1 = Node(10)
node2 = Node(20)
node3 = Node(30)
# Link them
node1.next = node2
node2.next = node3
# Head of the list
head = node1
Here, even if each node exists at a different memory address,
the .next pointer connects them all — forming the complete linked list.
🚀 Key Takeaway
Linked Lists in Memory show that:
“The strength of linked lists isn’t where they’re stored — it’s how they’re connected.”
This connection logic forms the foundation for dynamic data structures like Stacks, Queues, and Graphs.