# Which Is Called FIFO Data Structure?

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Scott Campbell

Which Is Called FIFO Data Structure?

A FIFO data structure, also known as a queue, is an abstract data type that follows the First-In-First-Out principle. In other words, the first element inserted into the queue is the first one to be removed. Think of it as a line of people waiting for a bus – the person who arrives first is the one who gets on the bus first.

## How Does a FIFO Data Structure Work?

In a FIFO data structure, elements are added to one end of the queue called the rear, and they are removed from the other end called the front. This ensures that elements are processed in the order they were inserted.

To visualize this process, imagine a queue represented by an array:

• The rear initially points to -1, indicating that there are no elements in the queue.
• When an element is inserted, it increments rear by 1 and adds the element at that index.
• When an element is removed, it increments front by 1 and returns the element at that index.

## Common Operations on FIFO Data Structures:

A FIFO data structure supports several operations:

### Enqueue

The enqueue operation adds an element to the rear of the queue. It takes constant time as it only involves incrementing rear and assigning a value at that index. The syntax for enqueue operation is:

```enqueue(element)
```

### Dequeue

The dequeue operation removes an element from the front of the queue. It also takes constant time as it only involves incrementing front. The syntax for dequeue operation is:

```dequeue()
```

### Peek

The peek operation returns the element at the front of the queue without removing it. It is a constant time operation. The syntax for peek operation is:

```peek()
```

## Applications of FIFO Data Structures:

FIFO data structures are widely used in various applications, including:

• Job scheduling: In operating systems, a queue is used to manage processes waiting to be executed.
• Buffering: Queues are used to buffer data between two components that operate at different speeds.
• Breadth-first search (BFS): BFS algorithm uses a queue to explore nodes level by level in a graph or tree.
• Print spooling: When multiple print jobs are sent to a printer, they are stored in a queue and printed one by one.

In conclusion, a FIFO data structure or queue follows the First-In-First-Out principle. It is an essential concept in computer science and finds applications in various domains.