- Janarthanan Soundararajan
A Glimpse of Modern JavaScript - Part 1
Updated: Jan 17, 2020
Once a client-side scripting language, but now we can use JavaScript for backend development, mobile application, web, and many more. JavaScript has evolved a lot in the past decade. Its syntax is more modern and easy to use. JavaScript is a dynamic and loosely typed language. But modern JS is more mature; So in this post, we’ll see some important improvements and features of the modern JavaScript.

Arrow Function
Arrow functions are similar to normal functions, but its syntax is a little different. See in the following example.
let and const
'let' and 'const' keywords are used to create the variables in modern Javascript. Variable created using 'let' has a block-level scope and 'const' for creating the constant variable which value cannot be changed.
Spread Operator
Spread operator (...) also called spread syntax using iterable in JavaScript. It helps to expand in places where zero or more than zero elements. Spread operators mostly useful in destructuring.
Template Literals
Before template literals, '+' operator used to concatenate the string and expressions. But we can use the expressions inside the string using the template literals. It also supports multi-line string.
for..of
A loop for iterable objects like Array.
Class
JavaScript does not support Object Orientation, which is a prototype-based language. But we can use the Class just like other Object Oriented languages.
for..in
It is similar to 'for..of' loop which helps to iterate the key-value pair JavaScript Objects. See the following example.
Like this article? Please check out part 2 of the 'A Glimpse of Modern JavaScript'.
Promise
Async/Await
Map and WeakMap
Set and WeakSet
A Glimpse of Modern JavaScript - Part 2
I hope the above mentioned Modern JS topics are useful. Thank you for reading!