Front End Technology Articles - Page 603 of 860

Peeking a Queue means getting the value at the head of the Queue. So we can implement the peek function as follows − EXamplepeek() {    if (isEmpty()) {       console.log("Queue Underflow!");       return;    }    return this.container[0]; }You can check if this function is working fine using − Examplelet q = new Queue(2); q.enqueue(3); q.enqueue(4); console.log(q.peek()); q.display();OutputThis will give the output −3 [ 3, 4 ]As you can see here, peek() differs from dequeue in that it just returns the front value without removing it.

Dequeuing elements from a Queue means removing them from the front/head of the queue. We are taking the start of the container array to be the head of the queue as we'll perform all operations with respect to it.Hence, we can implement the pop function as follows − Exampledequeue() {    // Check if empty    if (this.isEmpty()) {       console.log("Queue Underflow!");       return;    }    return this.container.shift(); }You can check if this function is working fine using − Examplelet q = new Queue(2); q.dequeue(); q.enqueue(3); q.enqueue(4); console.log(q.dequeue()); q.display();OutputThis will give the output −Queue Underflow! 3 [ ... Read More

In JavaScript, there is no such data structure concept as a Queue like other programming languages. But you can implement a queue in JavaScript using an array object. You can perform all the operations such as push() method to add element at end and shift() to remove first element. The following diagram will give a clear understanding of the queue data structure and its principles (FIFO): A Queue is a linear data structure that follows the FIFO (First In, First Out) principle. In JavaScript, it is used to store and manage elements of similar or different types. Here is ... Read More

Though Arrays in JavaScript provide all the functionality of a Queue, let us implement our own Queue class. Our class will have the following functions − enqueue(element): Function to add an element in the queue. dequeue(): Function that removes an element from the queue. peek(): Returns the element from the front of the queue. isFull(): Checks if we reached the element limit on the queue. isEmpty(): checks if the queue is empty. clear(): Remove all elements. display(): display all contents of the arrayLet's start by defining a simple class with a constructor that takes the max size of the queue and a helper function that'll help us ... Read More

In this article, we are going to discuss the queue data structure in JavaScript. It is a linear data structure where the enqueue and dequeue of elements follow the FIFO (first in first out sequence). The queue is open at both ends. One end is always used to insert data and the other is used to remove data. Here, we use two pointers rear and front. The rear is used to insert the data and the front is used to remove the data. A real-world example of the queue can be a single-lane one-way road, where the vehicle enters first, ... Read More

Here is the complete implementation of the Stack class −Exampleclass Stack {    constructor(maxSize) { // Set default max size if not provided       if (isNaN(maxSize)) {          maxSize = 10;       }       this.maxSize = maxSize; // Init an array that'll contain the stack values.       this.container = [];    }      display() {       console.log(this.container);    }      isEmpty() {       return this.container.length === 0;    }      isFull() {       return this.container.length >= this.maxSize;    }   ... Read More

Consider a simple stack class in Javascript. Exampleclass Stack {    constructor(maxSize) {       // Set default max size if not provided       if (isNaN(maxSize)) {          maxSize = 10;       }       this.maxSize = maxSize; // Init an array that'll contain the stack values.       this.container = [];    }    // A method just to see the contents while we develop this class    display() {       console.log(this.container);    }    // Checking if the array is empty    isEmpty() {   ... Read More

Consider a simple stack class in Javascript. Exampleclass Stack {    constructor(maxSize) {       // Set default max size if not provided       if (isNaN(maxSize)) {          maxSize = 10;       }       this.maxSize = maxSize; // Init an array that'll contain the stack values.       this.container = [];    }    // A method just to see the contents while we develop this class    display() {       console.log(this.container);    }    // Checking if the array is empty    isEmpty() {   ... Read More

Consider a simple stack class in Javascript.Exampleclass Stack {    constructor(maxSize) {       // Set default max size if not provided       if (isNaN(maxSize)) {          maxSize = 10;       }       this.maxSize = maxSize; // Init an array that'll contain the stack values.       this.container = [];    }    // A method just to see the contents while we develop this class    display() {       console.log(this.container);    }    // Checking if the array is empty    isEmpty() {   ... Read More

Consider the following stack class in Javascript with few small helper functions.Exampleclass Stack {    constructor(maxSize) {       // Set default max size if not provided       if (isNaN(maxSize)) {          maxSize = 10;       }       this.maxSize = maxSize; // Init an array that'll contain the stack values.       this.container = [];    }    // A method just to see the contents while we develop this class    display() {       console.log(this.container);    }    // Checking if the array is ... Read More