Since its creation in 1995, JavaScript has gone from strength to strength. Initially conceived as a simple scripting language for animating web pages, it quickly became one of the pillars of web development.
However, despite its growing popularity, JavaScript had its shortcomings, particularly in terms of structure and functionality. In 2015, a major update to the language was introduced, promising to irrevocably change the way developers would write JavaScript code. This update, known as ECMAScript 2015 or ES6, introduced a series of new features that not only made the language more powerful, but also simplified its syntax, making JavaScript code cleaner, more efficient and easier to understand.
New ES6 features
Let’s take a closer look at some of the most emblematic and useful features introduced by ES6. The table below gives you an overview, with an example of how to use them.
| Let and Const | New variable declarations | let allows a block scope for variables. const defines a constant that cannot be reassigned. |
let x = 10; const y =20; |
|---|---|---|---|
| Arrow Functions | Functions with a new syntax | They allow for a shorter syntax | (a, b) => a + b |
| Classes | Object-Oriented Model for JavaScript | Introduces object-oriented programming with classes, constructors, and inheritance | class Person { constructor(name) { this name = name; } } |
| Modules | Divide the code into importable modules | Allows you to isolate parts of the code for better organization and reuse | import { func } from'module'; |
| Destructuring | Extract data from tables/objects | A concise way to extract values from arrays or objects and assign them to variables. | const [a, b] = [1, 2]; |
| Default settings | Default values for functions | Allows you to set default values for function parameters | function greet(name = "Doe") { return Hello, ${name}! ; } |
| Promises | Managing asynchronous operations | Provides a cleaner way to handle asynchronous operations compared to callbacks. | new Promise((resolve, reject) => { /* */ }); |
| Spread and Rest Operators | Spread and Rest Operators | The spread operator decomposes elements. The rest operator groups elements into an array. |
const nums = [1, 2, 3]; const [a, rest] = nums; |
| Template Literals | Multi-line and interpolated strings | Allows you to embed expressions within strings and create multi-line strings | const greeting = `Hello, ${name}! `; |
Benefits of ES6
Adopting ES6 isn’t just about using new features or modernizing code. This JavaScript language update offers tangible benefits that can significantly improve code efficiency, readability and maintenance. Let’s take a closer look at some of these benefits:
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Cleaner and more readable code | With the introduction of arrow functions, template literals, and destructuring syntax, JavaScript code has become more concise and expressive. These features reduce code verbosity, making it easier to read and understand. |
|---|---|---|
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Enhanced object-oriented programming | With the introduction of classes and inheritance, JavaScript has strengthened its support for object-oriented programming. This makes it easier to create robust code structures and reuse code, especially for large projects. |
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Better management of asynchrony | Promises and later async/await functions (introduced in ES7) have transformed how developers handle asynchronous operations. These features have reduced code complexity, avoiding the typical callback entanglement. |
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Modularity and code reusability | With the module system, developers can now better organize their code, dividing it into reusable modules, thus improving maintenance and collaboration on projects. |
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Security and bug prevention | Features such as let and const limit the scope of variables and prevent accidental reassignments, thus reducing the risk of common errors. |
Transpilation: making ES6 compatible with all browsers
ES6 brought a host of new features and enhancements to the JavaScript language.
A major challenge then arose: how to ensure that code written via ES6 will work in all browsers, including those that don’t natively support these new features?
The answer lies in a process called transpilation.
What is transpilation?
Transpilation is the process of converting source code written in one version of the language to another version that is generally more widely supported. In the context of ES6, this means converting ES6 code to an earlier version of JavaScript (often ES5) that is supported by the majority of browsers.
Why is this necessary?
Although most modern browsers have started to support ES6, there are still a large number of users using older browsers or versions that don’t fully support ES6. To ensure a smooth, error-free user experience, transpilation is essential.
Transpilation with Babel
Considerations
- Performance: It can add overhead to the code, so performance testing is essential.
- Polyfills: Some objects or methods introduced in ES6, such as Promise or Array.prototype.includes, cannot be transpiled. Instead, a polyfill is used to provide this functionality in older browsers.
- Configuration: Babel, like other transpilers, offers a multitude of configuration options. It’s essential to take the time to configure them correctly.
To conclude
ES6 marks a major step in the evolution of JavaScript, enriching the language with powerful features and more elegant syntax, making development more intuitive and powerful.
With transpilation guaranteeing its compatibility, adopting ES6 is the right choice for any developer wishing to stay at the cutting edge of modern web development.
