Front End Technology Articles - Page 468 of 652

The delete method checks if a value already exists in the set, if it does, then it removes that value from the set. We can implement it as follows &minusl Exampledelete(val) {    if (this.has(val)) {       delete this.container[val];       return true;    }    return false; }You can test this using − Exampleconst testSet = new MySet(); testSet.add(1); testSet.add(2); testSet.add(5); testSet.delete(5); testSet.delete(2); testSet.display(); console.log(testSet.has(5)); console.log(testSet.has(20)); console.log(testSet.has(1));OutputThis will give the output −{ '1': 1} False False TrueIn ES6, you use the delete function as follows − Exampleconst testSet = new MySet(); testSet.add(1); testSet.add(2); testSet.add(5); testSet.delete(5); ... Read More

Let's create a MySet class so that it doesn't hide the actual set class in JS. We'll create a container object that'll keep track of all our values that we add to the set. We'll also create a display function that prints the set for us. Exampleclass MySet {    constructor() {       this.container = {};    }    display() {       console.log(this.container);    } }In ES6, you can directly create a set using the Set class. For example,  Exampleconst set1 = new Set(); const set2 = new Set([1, 2, 5, 6]);Checking for membershipThe has method checks ... Read More

Whenever you want to store unique elements in a container for which the order doesn't matter and you mainly want to use it to check for membership of different objects.Sets are also useful when you want to perform operations like union, intersection, a difference like you do in mathematical sets.Let's look at both how we can define our own set and use the existing one in ES6.Methods we'll implementThe ES6 set API provides some methods. We'll implement these methods in our implementation and also look at how to use them using the built-in class.add() −  Adds a new element to the ... Read More

A set is an abstract data type that can store certain values, without any particular order and no repeated values. It is a computer implementation of the mathematical concept of a finite set. Unlike most other collection types, rather than retrieving a specific element from a set, one typically tests a value for membership in a set.

Circular Linked List is a variation of the Linked list in which the first element points to the last element and the last element points to the first element. Both Singly Linked List and Doubly Linked List can be made into a circular linked list.

Here is the complete implementation of the DoublyLinkedList Class −Exampleclass DoublyLinkedList {    constructor() {       this.head = null;       this.tail = null;       this.length = 0;    }    insert(data, position = this.length) {       let node = new this.Node(data);       // List is currently empty       if (this.head === null) {          this.head = node;          this.tail = node;          this.length++;          return this.head;       }       // Insertion at ... Read More

Removing an element is very easy in a linked list. We just need to get rid of the node we want to remove, ie, lose its reference. There are 3 cases we need to consider −Removing an element from head: In this case, we can simply assign head = head.next and remove the previous link from the next element. This way we'll lose the reference of the first element. And out head will start pointing to the second element.Removing an element from the tail: In this case, we can simply assign the node.next of second last node to be null ... Read More

In this article, we are going to discuss a Doubly Linked List Class data structure in JavaScript. This is a linear data structure. Doubly linked lists are almost the same as a singly linked list in all operations, we just need to keep track of one extra link per node. In singly linked lists, we just had next links, in doubly linked lists, we have 2 links, next and prev. Doubly linked lists are represented as − Note that in the class itself, we also need to keep track of the tail(last element). Example In this example, we understand ... Read More

Here is the complete implementation of the LinkedList class −  Exampleclass LinkedList {    constructor() {       this.head = null;       this.length = 0;    }    insert(data, position = this.length) {       let node = new this.Node(data);       if (this.head === null) {          this.head = node;          this.length++;          return this.head;       }       let iter = 1;       let currNode = this.head;       while (currNode.next != null && iter < position) { ... Read More

Removing an element is very easy in a linked list. We just need to get rid of the node we want to remove, ie, lose its reference. There are 3 cases we need to consider −Removing an element from head: In this case, we can simply assign head = head.next. This way we'll lose the reference of the first element. And out head will start pointing to the second element. Removing an element from the tail: In this case, we can simply assign the node.next of second last node to be null and we'll get rid of the last element from ... Read More