# List Interface - LinkedList

* **Pros and Cons of Using Array**

1. Pros : Array is simple structure and the access time is short.
2. Cons : Immutable size. when Add, Remove Non-sequential data, it takes some time. But when Add, Remove sequential data from the end, it is fast.\
   **1. Create bigger Array.**\
   **2. Copy data.**\
   **3. Change reference.**

* **Background that LinkedList**

LinkedList supplement the cons of Array(immutable size, time to Add\&Remove)

* **LinkedList Type**

1. (Single)LinkedList : It has not good accessibility to each node.
2. Doubly LinkedList : It improves accessibility than Single LinkedList.
3. Doubly Circular LinkedList : Tail node connects head node and vice versa.

* **Performance Comparation between ArrayList and LinkedList**
* Data Structures : **Array-based(Sequential)** vs. **Connection-based(Non-Sequential).**

| Collection | Read Data | Accessibility | Description                                                           |
| ---------- | --------- | ------------- | --------------------------------------------------------------------- |
| ArrayList  | Fast      | Good          | <p>Sequential Add, Remove are fast.</p><p>Inefficient memory use.</p> |
| LinkedList | Slow      | Bad           | Much more data, worse accessibility.                                  |