Top 10 Most Exciting ES6 Features in JavaScript

Introduction

Throughout the years, JavaScript, one of the most widely used programming languages, has seen remarkable change.

One of the most significant milestones in its journey was the release of ECMAScript 6 (ES6), also known as ECMAScript 2015.

In this blog post, we’ll delve into the top 10 ES6 features in Javascript to facilitate your informed decision when choosing between Java and Javascript for development. Also, please read our article on the top 9 JavaScript frameworks to get valuable insights into your choice.

What is ECMAScript 6?

The latest ECMAScript language specification standard version is ES6, or ECMAScript 2015. Furthermore, it sets the modern standard for Javascript implementation, surpassing ES5 in popularity due to its enhanced features and improved syntax.

Additionally, it introduces many new features in es6 and es6 syntax enhancements that have revolutionized how developers write JavaScript code.

The JavaScript language has undergone significant changes with ES6. Several enhancements have been made to JavaScript programming to make it more enjoyable.

There are many keywords and operators to make programming easier, including rest and spread operators, let and const, template literals, modules, classes, and many more. Before you hire skilled Javascript developers, let’s discuss some excellent ES6 features in Javascript that developers can use in coding.

Benefits of ES6

ES6 (ECMAScript 2015) has several features that streamline JavaScript development and offer numerous benefits:

Improved Readability: ES6 features like arrow functions and template literals streamline the development process and make it more concise and readable.

Enhanced Maintainability: Classes and modules organize the code in modular form and help the developer in code maintenance and scalability.

Safer Variable Scoping: Block-scoped variables (let and const) prevent hoisting issues, reducing bugs and enhancing code reliability.

Default Parameters and Rest Parameters: These features simplify the handling of functional parameters and enhance the code usability.

Destructuring Assignment: These features of es6 help developers to easily extract values from objects and arrays and make the code more expressive by reducing verbosity.

Convenient Array/Object Manipulation: The spread operator simplifies tasks like array concatenation and object cloning, reducing the complexity of operations.

Setting defaults for function parameters

To get default values for function parameters in the past, you’d have to do something like this:

function findPower(val, exponent) {
         exponent = exponent || 2
      
         // ...
      }

Developers can create and default the parameters by using the new default parameters functionality.

function findPower(value, exponent = 2) {
         // The rest of your code
      }
      findPower(1, undefined) // exponent defaults to 2

Extracting Data from Arrays and Objects with Destructuring

Developers can extract values from arrays and objects by destructuring them and then exposing them as separate variables.

Destructuring has a wide range of applications, including situations where specific values from a bigger collection are required.

It provides a technique for quickly obtaining that value via a built-in feature of the language.

A Destructuring object syntax is with ‘ { } ‘ and the destructuring array syntax is with square brackets ‘ [ ] ’

Array case: const [one, two] = [1, 2]
      Object case: const {a, b} = { a: ‘a’, b: ‘b’ }

For instance, Destructuring Example 1:

function functionName() {
        return [name, age]
          }
      const [name,age] = functionName()

For instance, Destructuring Example 2:

const [first, second, ...theReaming] = my_array_elements

Destructuring Example 3:

var person = {
        name: "Alex", 
        gender: Male 
      }
      
      var name = person.name
      var gender= person.gender
      
      Using Destructuring in ES6, you can grab object values:
      
      const { name, title, data } = person

Checking Array Values with Array includes() method

The built-in.includes() method for Arrays provides a quick way to see if a value is included anyplace in the array.

If the array contains the supplied value, the method will return true else return false.

You may finally say goodbye to array. indexOf(item) === -1 indefinitely.

[12, 23].includes(12) // returns true

[12, 23].includes(4) // returns false

Allowing Extra Arguments in Functions

Rest parameters allow functions to collect additional arguments in addition to the ones they’ve already defined.

After that, the contents of these arguments are gathered into an array.

This allows a function to capture and parse additional parameters, allowing for many more optimization possibilities than were previously available through the arguments object.

Rest parameters now work with arrow functions, which is excellent because arrow functions previously didn’t have this capacity because the arguments object didn’t exist within them.

function combine(joiner, ...args) {
        // args is an actual Array
        return args.join(joiner)
      }
      combine('_', 1, 2, 3,4,5) // returns '1_2_3_4_5

Expanding Arrays with the Spread Operator

The spread operator is a versatile utility that is now available in JavaScript.

Expanding an array into arguments for functions or array literals is a valuable feature.

Reusing values, for instance, is beneficial because it requires a smaller footprint to store and call them due to the spread.

The spread operator is useful in functional parameters

const numbersArray = [1, 2, 3]
      findSum(...numbersArray)
      
      // same as
      findSum(1, 2, 3)
      
      Using the spread operator in array literal parameters:
      
      const array1 = [1, 2]
      
      const array12= [...array1 , 3, 4]
      // array2: [1, 2, 3, 4]

Arrow Functions

ES6 arrow functions provide you with an alternative way to write a shorter syntax compared to the function expression.

The following example defines a function expression that returns the sum of two numbers:

let sum= function (a, b) {
           return a + b;
      };
      
      console.log(sum(100, 200)); // 300

The following example is equivalent to the above add() function expression but uses an arrow function instead:

let sum= (a, b) => x + y;
      console.log(sum(100, 200)); // 300

Multi-Line String

With the arrival of Template Literals, it’s finally super easy to produce multi-line strings. Previously, we had to use the \n or separate string concatenation which was messy and difficult to read. Finally, it’s easier now. ES6 for the win;

// Old way
      
      const multiLine = "first \n second";
      // ES6 new way
      
      const multiLine = `first
      2️second`;
      
      /* RESULT
      first
      second
      */

Template Literals

ES6 introduces very simple string templates along with placeholders for the variables.

The syntax for using the string template is $ { PARAMETER } and is used inside of the back-ticked string.

let name = `My name is ${firstName} ${lastName}`

Promises

In ES6, Promises are used for asynchronous execution.

However, we can use promises with the arrow function…

var asyncCall = new Promise((resolve, reject) => {
        // do something here
        resolve();
      }).then(()=> { 
        console.log(‘Done’);
      })

Modules

Modules were previously not supported natively in JavaScript.

Furthermore, Modules are ES6 new features where each module is represented by a separate “.js” file.

We can import or export variables, functions, classes, or any other component from/to different files and modules using the “import” or “export” declaration in a module.

export var num = 100;
      
      export function name(fullName) { 
        // data
      };
      import {num, name} from 'module';
      console.log(num); // 100

Conclusion

ECMAScript 6 (ES6) has greatly improved JavaScript, making it more powerful, readable, and maintainable. The features we’ve explored in this blog post, including arrow functions, template literals, destructuring, spread/rest operators, block-scoped variables, classes, modules, default parameters, promises, and Map/Set data structures, have transformed the JavaScript landscape. As a developer, mastering these ES6 features in Javascript is essential for writing modern, efficient, and maintainable JavaScript code.

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