Javascript

Dhananjay Kumar , Microsoft Most Valuable Professional , Google Developer Expert, Trainer and Consultant

Closures in JavaScript: Video

A JavaScript closure is a function which remembers the environment in which it was created. We can think of it as an object with one method and private variables. JavaScript closures are a special kind of object which contains the function and the local scope of the function with all the variables (environment) when the … Continue reading Closures in JavaScript: Video

Dhananjay Kumar , Microsoft Most Valuable Professional , Google Developer Expert, Trainer and Consultant

Master RxJS: Part 2 – What is an observer

This is the second post in the Master RxJS series. The first post is a video tutorial that explains, why RxJS Watch it here: https://www.youtube.com/watch?v=GfuGIh-Bmxw In this post, we will discuss an observer in RxJS. An observer is an object with three call-back functions to subscribe to the notifications from an Observable. Too much technical … Continue reading Master RxJS: Part 2 – What is an observer

Dhananjay Kumar , Microsoft Most Valuable Professional , Google Developer Expert, Trainer and Consultant

How to make the length of an Array read-only in JavaScript

Sometimes, you may come across a requirement that once the array is created, its length should not be changed. In this blog post, let us explore how you can achieve that. Let us say you have an array as shown below, let foo = ['1', '11']; console.log(foo.length); // 2 console.log(foo[1]); //11 As you see, the length of the array is 2, and … Continue reading How to make the length of an Array read-only in JavaScript

Dhananjay Kumar , Microsoft Most Valuable Professional , Google Developer Expert, Trainer and Consultant

Link Constructors prototypes to create Inheritance in JavaScript

In JavaScript, there are multiple ways to create an object. However, among all the most popular is using a function as a constructor.   A function returns a newly created object if it is called using the new, which is also known as Constructor Invocation Pattern. You can create a function constructor like any other … Continue reading Link Constructors prototypes to create Inheritance in JavaScript

Dhananjay Kumar , Microsoft Most Valuable Professional , Google Developer Expert, Trainer and Consultant

How Object.entries work internally in JavaScript

In JavaScript, the Object.entries method returns an array of object’s own enumerable properties. It returns properties as a [key, value] pair, where the key is a string. You can read enumerable properties as an array of key-value pairs using the Object.entries method as shown below, let Product = {     Title: 'Book',     Price: 120,     Author: undefined,     inStock: true } console.log(Object.entries(Product)); Since it returns … Continue reading How Object.entries work internally in JavaScript

Dhananjay Kumar , Microsoft Most Valuable Professional , Google Developer Expert, Trainer and Consultant

Working with objects in a JavaScript Arrow Function

The JavaScript Arrow function is a shorter way of writing a function expression. Let us say you have a function expression as below, var add = function (num1, num2) {     return num1 + num2; } The above function can refactor for a shorter syntax using the arrow function as below, var add = (num1, num2) => num1 + num2;  So, as you see, the arrow function provides a convenient and short syntax … Continue reading Working with objects in a JavaScript Arrow Function