24 lines
804 B
Markdown
24 lines
804 B
Markdown
# Queue
|
|
- The Queue interface is present in the `java.util` package.
|
|
- It is an ordered list of objects that follows the **FIFO** (First-In-First-Out) principle.
|
|
|
|
## Characteristics of a Queue
|
|
- The Queue is used to insert elements at the end of the queue and removes elements from the beginning of the queue.
|
|
- It supports all methods of Collection interface including insertion, deletion etc.
|
|
- LinkedList, ArrayBlockingQueue and PriorityQueue are the most commonly used implementations.
|
|
|
|
## Declaration
|
|
|
|
`Queue<Obj> queue = new PriorityQueue<Obj> ();`
|
|
|
|
## Important operations
|
|
|
|
| Operations | Description |
|
|
| ----------- | ----------- |
|
|
|Enqueue|Adds an item to the queue|
|
|
|Dequeue|Removes an item from the queue|
|
|
|Front|Gets the front item from the queue|
|
|
|Rear|Gets the last item from the queue|
|
|
|
|
|