> For the complete documentation index, see [llms.txt](https://alex-myznikov.gitbook.io/adsjs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://alex-myznikov.gitbook.io/adsjs/api/stacks-and-queues/adaptableheappriorityqueue.md).

# AdaptableHeapPriorityQueue

### new AdaptableHeapPriorityQueue()

```typescript
/**
 * Creates an instance of AdaptableHeapPriorityQueue.
 *
 * @param elements List of elements to create the new priority queue with.
 * @param compare Comparison function for element search. Elements are compared as numbers by default.
 */
constructor(elements: K[] | [K, V][] = [], protected compare: CompareFunc<K> = compareAsNumbers)
```

### length

```typescript
length: number
```

Number of elements in the queue. This field is read only.

#### Examples:

```typescript
import { SortedPriorityQueue } from 'ads-js/queues';

const queue = new SortedPriorityQueue();

queue.length === 0; // true
queue.enqueue(1);
queue.length === 1; // true
```

### clear()

```typescript
/**
 * Clears the queue.
 */
clear(): void;
```

### dequeue()

```typescript
/**
 * Removes the first element from the front of the queue and returns it.
 * Throws an error if the queue is empty.
 *
 * @returns Removed element.
 */
dequeue(): T;
```

### enqueue()

```typescript
/**
 * Adds element at the rear of the queue.
 *
 * @param element Element to add.
 */
enqueue(element: T): void;
```

### getFirst()

```typescript
/**
 * Gets element from the front of the queue without its removal.
 *
 * @returns Queue element.
 */
getFirst(): T;
```

### isEmpty()

```typescript
isEmpty(): boolean
```

> Running time O(1)

Checks whether the queue is empty or not.

#### Returns:

TRUE if the queue is empty, FALSE otherwise.

#### Examples:

```typescript
import { SortedPriorityQueue } from 'ads-js/queues';

const queue = new SortedPriorityQueue();

queue.isEmpty(); // true
queue.enqueue(1);
queue.isEmpty(); // false
```

### remove()

```typescript
/**
 * Removes element from the queue by locator and returns it. Throws an error if the queue is empty
 * or the locator is not valid.
 *
 * @param locator Locator of the element.
 * @returns Removed element.
 */
remove(locator: Locator<K | [K, V]>): K | [K, V];
```

### update()

```typescript
/**
 * Updates element in the queue by locator. Throws an error if the locator is not valid.
 *
 * @param locator Locator of the element.
 * @param element The element updatement.
 */
update(locator: Locator<K | [K, V]>, element: K | [K, V]): void;
```