2 basic FIFO queue implementations

A simple way to implement a temporary queue data structure in Go is to use a slice:

• to enqueue you use the built-in append function, and
• to dequeue you slice off the first element.

var queue []string

queue = append(queue, "Hello ") // Enqueue
queue = append(queue, "world!")

for len(queue) > 0 {
	fmt.Print(queue[0]) // First element
	queue = queue[1:]   // Dequeue
}

Hello world!

Watch out for memory leaks

You may want to remove the first element before dequeuing.

// Dequeue
queue[0] = "" // Erase element (write zero value)
queue = queue[1:]

Warning: The memory allocated for the array is never returned. For a long-living queue you should probably use a dynamic data structure, such as a linked list.

Linked list

The container/list package implements a doubly linked list which can be used as a queue.

queue := list.New()

queue.PushBack("Hello ") // Enqueue
queue.PushBack("world!")

for queue.Len() > 0 {
	e := queue.Front() // First element
	fmt.Print(e.Value)

	queue.Remove(e) // Dequeue
}

Hello world!

More code examples

Go blueprints: code for com­mon tasks is a collection of handy code examples.

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