API

new Denque() -> Denque#

Creates an empty double-ended queue with initial capacity of 4.

var denque = new Denque();
denque.push(1);
denque.push(2);
denque.push(3);
denque.shift(); //1
denque.pop(); //3

new Denque(Array items) -> Denque#

Creates a double-ended queue from items.

var denque = new Denque([1,2,3,4]);
denque.shift(); // 1
denque.pop(); // 4

push(item) -> int#

Push an item to the back of this queue. Returns the amount of items currently in the queue after the operation.

var denque = new Denque();
denque.push(1);
denque.pop(); // 1
denque.push(2);
denque.push(3);
denque.shift(); // 2
denque.shift(); // 3

unshift(item) -> int#

Unshift an item to the front of this queue. Returns the amount of items currently in the queue after the operation.

var denque = new Denque([2,3]);
denque.unshift(1);
denque.toString(); // "1,2,3"
denque.unshift(-2);
denque.toString(); // "-2,-1,0,1,2,3"

pop() -> dynamic#

Pop off the item at the back of this queue.

Note: The item will be removed from the queue. If you simply want to see what's at the back of the queue use peekBack() or .peekAt(-1).

If the queue is empty, undefined is returned. If you need to differentiate between undefined values in the queue and pop() return value - check the queue .length before popping.

var denque = new Denque([1,2,3]);
denque.pop(); // 3
denque.pop(); // 2
denque.pop(); // 1
denque.pop(); // undefined

Aliases: removeBack

shift() -> dynamic#

Shifts off the item at the front of this queue.

Note: The item will be removed from the queue. If you simply want to see what's at the front of the queue use peekFront() or .peekAt(0).

If the queue is empty, undefined is returned. If you need to differentiate between undefined values in the queue and shift() return value - check the queue .length before shifting.

var denque = new Denque([1,2,3]);
denque.shift(); // 1
denque.shift(); // 2
denque.shift(); // 3
denque.shift(); // undefined

toArray() -> Array#

Returns the items in the queue as an array. Starting from the item in the front of the queue and ending to the item at the back of the queue.

var denque = new Denque([1,2,3]);
denque.push(4);
denque.unshift(0);
denque.toArray(); // [0,1,2,3,4]

peekBack() -> dynamic#

Returns the item that is at the back of this queue without removing it.

If the queue is empty, undefined is returned.

var denque = new Denque([1,2,3]);
denque.push(4);
denque.peekBack(); // 4

peekFront() -> dynamic#

Returns the item that is at the front of this queue without removing it.

If the queue is empty, undefined is returned.

var denque = new Denque([1,2,3]);
denque.push(4);
denque.peekFront(); // 1

peekAt(int index) -> dynamic#

Returns the item that is at the given index of this queue without removing it.

The index is zero-based, so .peekAt(0) will return the item that is at the front, .peekAt(1) will return the item that comes after and so on.

The index can be negative to read items at the back of the queue. .peekAt(-1) returns the item that is at the back of the queue, .peekAt(-2) will return the item that comes before and so on.

Returns undefined if index is not a valid index into the queue.

var denque = new Denque([1,2,3]);
denque.peekAt(0); //1
denque.peekAt(1); //2
denque.peekAt(2); //3

denque.peekAt(-1); // 3
denque.peekAt(-2); // 2
denque.peekAt(-3); // 1

Note: The implementation has O(1) random access using .peekAt().

Aliases: get

remove(int index, int count) -> array#

Remove number of items from the specified index from the list.

Returns array of removed items.

Returns undefined if the list is empty.

var denque = new Denque([1,2,3,4,5,6,7]);
denque.remove(0,3); //[1,2,3]
denque.remove(1,2); //[5,6]
var denque1 = new Denque([1,2,3,4,5,6,7]);
denque1.remove(4, 100); //[5,6,7]

removeOne(int index) -> dynamic#

Remove and return the item at the specified index from the list.

Returns undefined if the list is empty.

var denque = new Denque([1,2,3,4,5,6,7]);
denque.removeOne(4); // 5
denque.removeOne(3); // 4
denque1.removeOne(1); // 2

splice(int index, int count, item1, item2, ...) -> array#

Native splice implementation.

Remove number of items from the specified index from the list and/or add new elements.

Returns array of removed items or empty array if count == 0.

Returns undefined if the list is empty.

var denque = new Denque([1,2,3,4,5,6,7]);
denque.splice(denque.length, 0, 8, 9, 10); // []
denque.toArray() // [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
denque.splice(3, 3, 44, 55, 66); // [4,5,6]
denque.splice(5,4, 666,667,668,669); // [ 66, 7, 8, 9 ]
denque.toArray() // [ 1, 2, 3, 44, 55, 666, 667, 668, 669, 10 ]

isEmpty() -> boolean#

Return true if this queue is empty, false otherwise.

var denque = new Denque();
denque.isEmpty(); // true
denque.push(1);
denque.isEmpty(); // false

clear() -> void#

Remove all items from this queue. Does not change the queue's capacity.

var denque = new Denque([1,2,3]);
denque.toString(); // "1,2,3"
denque.clear();
denque.toString(); // ""