Skip to main content

Node.js (v.14): 2 Things to know.



Node.js version 14 is here!

As per the official site, Node.js 14 replaces Node.js 13 on 21st April 2020 as a current release.
This article will highlight 2 new JavaScript features included in version 14.
So, Let's dive deep and check each one.


1) Optional Chaining operator (?.) :

 We may have got error many times while conditioning a nested object.

For example:

var animal={
 dog:{
   name:'Charlie Bhalerao'
   }
}

if(animal.cat.name){
console.log(animal.cat.name,"executed")
}

So here we get an error as we do not have a 'cat' key present in the 'animal' object.
To avoid such issues, we are validating references in between,

if(animal.cat && animal.cat.name){
console.log(animal.cat.name,"executed")
}

So here we are checking if 'cat' property exist then only access 'name'.

But now there is no need to do this type of validations instead we can use optional chaining operator.

if(animal.cat?.name){
console.log(animal.cat.name,"executed")
}

Here JavaScript implicitly checks if 'animal.cat' is present then only access 'animal.cat.name' no need to check explicitly.


The same is applicable for function calls.
console.log(animal.eat?.());
Here instead of giving an error (function not defined), it will first check if the method is present then only it will call.
So it will definitely help to write more error-free code and will save a lot of time.





2) Nullish Coalescing operator (??) :
First, we will discuss the issue we face and then will see how it will help to overcome the issue.
Let see this example,
So here we want to check if 'flag' value is not null then assign that value or else assign null to it.


var flag=false;
const flagValue = flag?flag:null;
console.log(flagValue );//output will be null.

Here, though the 'flag' value is not null still its values is not assigned.

So to achieve our desired output we can use nullish coalescing operator.
It is a logical operator that returns right-hand side operand
when its left-hand side operand is null or undefined and otherwise returns its left-hand side operand.


var flag=false;
const flagValue = flag??null;
console.log(flagValue );//output will be flag.

Thus, In such use cases, we can use this operator.

I hope you found this article helpful.

Download the latest version here: https://nodejs.org/en/download/current/

Please do share your feedback in the comments section.
Subscribe this blog for more articles on Node.js and JavaScript.
You can also follow me on Twitter or Linkedin for the latest updates.

Written By:
Saurabh Joshi

Comments

Post a Comment

Popular posts from this blog

Node.js: Extract text from image using Tesseract.

In this article, we will see how to extract text from images using Tesseract . So let's start with this use-case, Suppose you have 300 screenshot images in your mobile which has an email attribute that you need for some reason like growing your network or for email marketing. To get an email from all these images manually into CSV or excel will take a lot of time. So now we will check how to automate this thing. First, you need to install Tesseract OCR( An optical character recognition engine ) pre-built binary package for a particular OS. I have tested it for Windows 10. For Windows 10, you can install  it from here. For other OS you make check  this link. So once you install Tesseract from windows setup, you also need to set path variable probably, 'C:\Program Files\Tesseract-OCR' to access it from any location. Then you need to install textract library from npm. To read the path of these 300 images we can select all images and can rename it to som...
1 comment
Read more

Globant part 1

 1)call,apply,bind example? Ans: a. call Method: The call method is used to call a function with a given this value and arguments provided individually. Javascript code: function greet(name) {   console.log(`Hello, ${name}! I am ${this.role}.`); } const person = {   role: 'developer' }; greet.call(person, 'Alice'); // Output: Hello, Alice! I am developer. In this example, call invokes the greet function with person as the this value and passes 'Alice' as an argument. b. apply Method: The apply method is similar to call, but it accepts arguments as an array. Javascript code: function introduce(language1, language2) {   console.log(`I can code in ${language1} and ${language2}. I am ${this.name}.`); } const coder = {   name: 'Bob' }; introduce.apply(coder, ['JavaScript', 'Python']); // Output: I can code in JavaScript and Python. I am Bob. Here, apply is used to invoke introduce with coder as this and an array ['JavaScript', 'Pyt...
Post a Comment
Read more

Maximizing MongoDB Performance: A Guide to Effective Indexing Strategies

Introduction: MongoDB, a leading NoSQL database, offers unparalleled flexibility and scalability. However, achieving optimal query performance in MongoDB often relies on implementing effective indexing strategies. In this article, we'll delve into various indexing techniques and provide real-world examples to demonstrate their impact on query performance. Single Field Index: Single field indexes are ideal for accelerating queries that filter, sort, or search based on a specific field. Let's consider a scenario where we have a collection of user profiles, and we frequently query users by their username field: db.users.createIndex({ "username": 1 }) This index significantly speeds up queries like: db.users.find({ "username": "john_doe" }) Compound Index: Compound indexes are invaluable when queries involve multiple fields. Suppose we have a collection of products and often filter by both category and price: db.products.createIndex({ "category...
Post a Comment
Read more