@datastructures-js/doubly-linked-list

@datastrucures-js/doubly-linked-list

node's data type: number, string, boolean, null, undefined.

Usage

const doublyLinkedListFn = require('@datastructures-js/doubly-linked-list');
const dll = doublyLinkedListFn();

API

.node(value)

creates a linked list node with a given value. The node object exposes the following functions:

• .setValue(value) sets the value of the node.
• .getValue() gets the value of the node
• .setNext(node) sets the next linkedListNode object.
• .getNext() gets the next linkedListNode object.
• .setPrev(node) sets the previous linkedListNode object.
• .getPrev() gets the previous linkedListNode object.

const n = dll.node('new_node');
console.log(n.getValue()); // new_node
console.log(n.getNext()); // null
console.log(n.getPrev()); // null

.addFirst(value)

adds a node of the given value at the beginning of the list.

dll.addFirst('n1');

.addLast(value)

adds a node of the given value at the end of the list.

dll.addLast('n4');

.addAfter(value, newValue)

adds a node with a given value after an existing value's node.

try {
  dll.addAfter('n1', 'n2');
  dll.addAfter('n33', 'n3');
}
catch (e) {
  console.log(e.message); // node n33 not found
}

.addBefore(value, newValue)

adds a node with a given value before an existing value's node.

try {
  dll.addBefore('n4', 'n3');
  dll.addBefore('n33', 'n3');
}
catch (e) {
  console.log(e.message); // node n33 not found
}

.find(value) finds a node by its value and returns a linked list node object.

const n3 = dll.find('n3');
console.log(n3.getValue()); // n3
console.log(n3.getNext().getValue()); // n4

.head()

returns the first dll node object in the list.

const head = dll.head();
console.log(head.getValue()); // n1

.tail()

returns the first dll node object in the list.

const tail = dll.tail();
console.log(head.getValue()); // n1

.traverse(cb)

traverse the dll from beginning to end and calls cb for each node

dll.traverse((n) => { console.log(n.getValue()); });
// n1
// n2
// n3
// n4

.traverseBackward(cb)

traverse the dll from end to beginning and calls cb for each node

dll.traverseBackward((n) => { console.log(n.getValue()); });
// n4
// n3
// n2
// n1

.remove(value)

remove the value's node - if exists - from the list.

dll.remove('n3');

.removeFirst()

removes the first node in the list.

dll.removeFirst(); // n1 removed

.removeLast()

removes the last node in the list.

dll.removeLast(); // n4 removed

.toArray()

converts the dll to an array

console.log(dll.toArray());
// ['n1', 'n2', 'n3', 'n4']

.count()

returns nodes' count in the list.

console.log(dll.count()); // 1

.clear()

removes all nodes from the list.

dll.clear();
console.log(dll.head()); // null
console.log(dll.count()); // 0

Build

grunt build

License

The MIT License. Full License is here