Linked list implementation using JavaScript

What is a Linked List? Linked list is a linear data structure in which data is stored in non-contiguous memory location. Data in a linked list is wrapped in an object which is commonly called as a node . Each node points (or links) to the next node in the sequence of a list. Unlike arrays, linked lists can easily grow or shrink with addition or removal of data. More detailed information about linked lists can be found here . What will I get from this article? In this article, you will learn about implementing Singly Linked List using JavaScript. Note that, this code is written for learning purpose, so, if you are planning to use this code or a piece of this code in your application, please make sure to have thorough testing in place. Implementation We will be executing our code using NodeJS, make sure it is installed in your system. We will have three files in our project directory. list-node.js – class repre

Calling APIs in sequence using async-await

 There are certain cases when we want to call some APIs in a sequence (order) to get some data. For example, let's say we want to fetch data of 1000 students of an university for some analysis. The API given to us fetches only 100 records at a time but supports pagination. Therefore, we need to call the API 10 times, one after the other to get these records. This can be achieved by Using plain old callbacks. Using a combination of promises and callbacks. Using modern JavaScript feature - async-await (both async and await are keywords). In this article we will discuss method 3 to solve this problem. We will see the implementation in action using an open API. We will be creating a console app using NodeJS (version 14.7 as of writing) and will be using axios  for making http calls. Setting up the project Create a directory where you want to keep your JavaScript code files. I have named my directory "api-sequence-async-await". Open your terminal or command prompt and run co

What is object destructuring and spread operator in JavaScript?

Object destructuring Object destructuring is a feature in JavaScript which allows us to assign values from arrays and properties from objects to distinct variables. This is also referred to as destructuring assignment . Examples Swapping two numbers let   x  =  5 ,  y  =  7 ; [ x ,  y ] = [ y ,  x ]; console . log ( x ,  y );  // 7 5 Taking out values from an array and assigning them to variables let   array  = [ 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ]; const  [,  a , , ,  b ,  c ] =  array ; console . log ( a ,  b ,  c );  // 2 5 6 Assigning remaining values to a variable let   array  = [ 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9 ]; const  [ x , ... y ] =  array ; console . log ( x ); console . log ( y ); // 1 // [ //   2, 3, 4, 5, //   6, 7, 8, 9 // ] Taking out properties from an object and assigning them to variables const   student  = {      name:   'Student 1' ,      rollNo:   45 ,      subject:   'Economics' ,   

What are filter, map and reduce functions in JavaScript?

These are in built functions which are available on arrays in JavaScript. In this article, we will talk about what these functions do and how they are used. filter – Array.prototype.filter This function returns a subset of an array containing those elements which satisfy a given condition in the form of a callback . Syntax newArray = someArray.filter(callback(element[, index, array])[, thisArg]) newArray is the filtered array. someArray is the original array. callback is the callback function. element is the current element of the array which is being processed by the filter function. index is the index of the current element. array is the original array. thisArg is the value to be used as this while executing the callback. If the callback function returns a truthy value then the element will be included in the new array otherwise it will be ignored. Examples Getting even numbers from a list of numbers let   numbers  = [ 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9 ,