Essential ES6 JavaScript Features Every JavaScript Developer Should Know
Tags: webdev, javascript, tutorial, programming
Published: 2024-05-01 11:03:25



As a developer, it's crucial to stay updated with recent technologies to remain relevant and streamline development processes. The newer the technology, the less work is required. That's why we'll be discussing the essential features of ES6 that you need to master.

In this article, we will examine the ES6 key features such as template literals, arrow function, Object and Array destructuring, and other related concepts within the context of functional programming paradigms in JavaScript ES6.

Before proceeding with this article, it's important to have a basic understanding of JavaScript, including variables, data types, control flow, and functions. If you're not familiar with these concepts or need a refresher, check out this article by MDN web docs.



**ECMASCRIPT6**

 ES6, short for ECMAScript 6, was developed to standardize JavaScript further, representing the sixth iteration of ECMAScript. 

 JavaScript ES6 introduces new syntax, enabling us to write less code for accomplishing complex tasks. Understanding ES6 features facilitates efficient coding.



**Key Features we will be looking at in this article: 
**

1. Arrow function
2. Template literals
3. Object 
4. Array destructuring
5. Set
6. Spread operator
7. Rest operator





-> **Arrow function**: Arrow functions provide a simpler and more straightforward method for creating functions compared to the traditional approach of using the 'function' keyword for declaration.


Arrow function syntax: 

  
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/0nb52t8zwjyhf3u8izwx.jpg)

Traditional vs Arrow function

The example below shows how traditional functions and arrow functions differ in their syntax.
 
The traditional way of declaring a function:

  
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/d3cr437i7idj6c0u7jj3.jpg)


Arrow function: 
   
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/907vc15xy5tvlj9f2jtv.jpg)

Notice the two methods perform the same function, but the arrow function provides a simpler way of declaring the function

-> **Template literals**: Template literals are a feature that allows you to embed expressions within string literals. Instead of concatenating strings using the '+' operator, template literals enclose the strings in backticks (` `) and utilize ${} to serve as placeholders.

Example: 
  
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/il1bs0ma1kzbl8dwwopb.jpg)

NB: We no longer need to concatenate strings when accessing the values of `firstName` and `lastName`. Instead, we can directly use `${}` placeholders to access them.


-> **Array Destructuring:** In ES6, array destructuring involves extracting values from an array and assigning them to separate variables.

Take a look at the example below:

Previously, accessing the values in the 'studentName' array was achieved using the following method:
  
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/9x8cgbnheujunsgixmzp.jpg)
  

But Array destructuring offers a straightforward approach to accessing values, requiring only a few simple steps.
  
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/dg5rzmqxfxd44kr8mhoa.jpg)


-> **Object Destructuring**: This works like array destructuring, but instead of arrays, it's about pulling out values from objects.

An example of object Destructuring

Previously, if we wanted to extract data from 'StudentDetail', we would have done so by:
  
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/81ijqnv08hq9s4dxd2wu.jpg)
  


With object destructuring, accessing them becomes easier using the following method:
 
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/g85lc0e6y2ra6xoo86y2.jpg)




-> **Set**: The Set method is used to retrieve only unique values from an array. It ensures that each value occurs only once within the set.

Set Syntax: 
   
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/iifd6sh2ozwdlulrpjk3.jpg)


Example: The “games" variable holds value for different kinds of games played; the `new Set` method can be used to return unique values ensuring no game appears more than once.
   
  


-> Spread operator: The 'Spread' operator iterates over an iterable element, such as a string, array, or object, and then spreads each value into individual items. This allows us to quickly copy them.

**Spread syntax**: (...)

Example: Spread operator allows us to split the elements in ‘hobby’ variables into a single item.
     
  
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/7qf0yc72xug5z09rh2o1.jpg)

Example 2: We can use the spread operator in an array too:
   
   
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/sihq9cedvq8kt2c0w51h.jpg)


-> **Rest operator**: The Rest operator has a similar syntax as the Spread operator. However, the Rest operator is used to gather the rest of the item into an array. It allows you to access the rest of the values in an element easily.

**Rest Syntax**:  (...) Followed by the name of the parameter. 

Example: We can access the first name of the students and use the rest operator to collect the remaining names of the students:
  
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/vjynii3re2y3zzm4l9tb.jpg)
 


**Note!**
 You can't place the rest operator at the beginning like this:
  
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/tezhs0b7qr43rfii92ts.jpg)
  
It will return an error if you try to use the rest operator this way!




**Conclusion**

  In this article, we have talked about essential features of ES6 you need to know as a developer. We started with the Arrow function, then we moved to template literals, array and object destructuring, and other related concepts. If you've reached this section, then you should be able to implement the following topics we talked about in your next project.

See you at the top!

**References**

 MDN web docs
 w3Schools