List implementations of List interface

List implementations of List interface

In Java, the `List` interface is a part of the Java Collections Framework, and it has several implementations that provide different behaviors and performance characteristics. Here are some common implementations of the `List` interface:

List implementations of List interface

1. ArrayList:

  • Implements a dynamic array that can grow or shrink as needed.
  • Provides fast random access to elements using their index.
  • Suitable for situations where frequent access or modifications to the list’s elements are required.

Example
```java
List<String> arrayList = new ArrayList<>();
```

2. LinkedList:

  • Implements a doubly-linked list data structure.
  • Provides fast insertion and deletion operations, especially at both ends of the list.
  • Slower random access compared to `ArrayList`.
  • Suitable for situations where frequent insertions or deletions are required.

Example
```java
List<String> linkedList = new LinkedList<>();
```

3. Vector:

  • Similar to `ArrayList` but is synchronized, i.e., it is thread-safe.
  • Each method of `Vector` is synchronized, which can lead to performance overhead in multi-threaded environments.
  • Less commonly used due to synchronization overhead.

Example
```java
List<String> vector = new Vector<>();
```

4. Stack:

  • Extends `Vector` and represents a last-in, first-out (LIFO) stack of objects.
  • Provides methods like `push()` and `pop()` for stack operations.

Example
```java
Stack<String> stack = new Stack<>();
```

5. CopyOnWriteArrayList:

  • Implements a thread-safe variant of `ArrayList`.
  • Creates a new copy of the underlying array whenever an element is added, modified, or removed.
  • Suitable for situations where the list is mainly read-intensive and writes are infrequent.

   –

Example
```java
List<String> copyOnWriteArrayList = new CopyOnWriteArrayList<>();
```

Summary:

  • ArrayList: Dynamic array with fast random access.
  • LinkedList: Doubly-linked list with fast insertions and deletions.
  • Vector: Synchronized version of `ArrayList`.
  • Stack: Last-in, first-out (LIFO) stack based on `Vector`.
  • CopyOnWriteArrayList: Thread-safe variant of `ArrayList` optimized for read-heavy scenarios.

Each implementation of the `List` interface has its advantages and use cases, so choosing the appropriate one depends on factors such as the required performance characteristics, thread safety requirements, and specific operations needed in the application.