How to implement a queue (First-In-First-Out) using a slice in Golang?

To implement a queue (First-In-First-Out) using a slice in Go, you can follow these steps:

Define a struct type for your queue that holds the underlying slice and two integer variables to track the front and rear indices of the queue:

type Queue struct {
    items []int
    front int
    rear  int
}

Define methods for the queue struct to perform queue operations such as Enqueue, Dequeue, IsEmpty, Size, and Front.

// Enqueue adds an element to the rear of the queue
func (q *Queue) Enqueue(item int) {
    q.items = append(q.items, item)
    q.rear++
}

// Dequeue removes and returns the front element of the queue
func (q *Queue) Dequeue() int {
    if q.IsEmpty() {
        panic("Queue is empty")
    }
    item := q.items[q.front]
    q.items = q.items[q.front+1:]
    q.rear--
    return item
}

// IsEmpty checks if the queue is empty
func (q *Queue) IsEmpty() bool {
    return q.front == q.rear
}

// Size returns the number of elements in the queue
func (q *Queue) Size() int {
    return q.rear - q.front
}

// Front returns the front element of the queue without removing it
func (q *Queue) Front() int {
    if q.IsEmpty() {
        panic("Queue is empty")
    }
    return q.items[q.front]
}

Create a new instance of the Queue struct and use the Enqueue and Dequeue methods to add and remove elements from the queue:

queue := Queue{}

queue.Enqueue(1)
queue.Enqueue(2)
queue.Enqueue(3)

fmt.Println(queue.Front()) // Output: 1

fmt.Println(queue.Dequeue()) // Output: 1
fmt.Println(queue.Dequeue()) // Output: 2

fmt.Println(queue.Size()) // Output: 1
fmt.Println(queue.IsEmpty()) // Output: false

Now you have successfully implemented a queue (First-In-First-Out) using a slice in Go.