In the developer world, JavaScript continues to be one of the most crucial languages for any professional to understand. V8 is Google’s approach to giving today’s developers a high-performance and open-source JavaScript Engine. As you may already know, a JavaScript engine is an interpretation program that executes JavaScript code. The engine can be implemented as a standard program, or as part of a just-in-time compiler.
The Google V8 JavaScript engine is written in C++ and used alongside Google Chrome – the open source Google browser. It implements the ECMAScript, and it can also run on Windows 7 or later, Linux systems using IA-32, and MacOS 10.5 or above. Depending on your preferences, you can run V8 on a standalone basis, or embed it into your C++ applications.
When Google decided to design V8, it was to increase the performance of their JavaScript execution strategies within modern web browsers. To offer exceptional speed and capabilities, V8 translates traditional JavaScript code into a more efficient machine code, instead of using interpreters. V8 also compiles JavaScript code into machine code by implementing something called a “Just-in-Time” compiler.
Getting to Know Google V8’s JavaScript System
Google’s V8 system implements the ECMA-262 specifications of ECMAScript, and it’s designed to compile and execute crucial JavaScript source code, as well as handling memory allocation for important objects, and getting rid of data the system no longer needs. The stop-the-world accurate and generational garbage collector is actually one of the most exciting parts of V8’s high-level performance.
As most developers will already know, the JavaScript language is most commonly used for browser client-side scripting. You can use JavaScript to manipulate Document Object Model examples, however, it’s worth noting that the DOM isn’t typically delivered by the JavaScript engine, but is provided through a browser instead. The same is true for V8 – Google Chrome is the entity providing the DOM. However, V8 provides all the operators, data types, functions, and objects provided by the ECMA standard.
V8 helps C++ applications to expose their own functions and objects to the JavaScript code. As a developer, it will be completely up to you to decide on what functions and objects you’ll want to expose to JavaScript. There are plenty of applications that do this, including Dashboard Widgets, Adobe Flash, and Yahoo! Widgets.
The Most Recent Release of Google V8
One of the things that helps Google to stay ahead of the curve with their JavaScript Engine, is the fact that the V8 is constantly updating to improve its performance and deliver better results. For instance, the beta 6.6 version of Google’s recent JavaScript engine is the latest one to be released, and it focuses on language features for JavaScript, as well as new code-caching capabilities.
For instance, in the new 6.6 version of V8, paragraph and line separator symbols can string literals together, matching JSON. In previous iterations, these symbols had been treated entirely as terminations in string literals and often resulted in a Syntax Error.
Aside from the changes to the JavaScript language, the new Google V8 version also brings a code cache execution option to the mix. This code caching feature allows developers to include more functions in the cache, with features that no longer need to be compiled in future page loading structures. Parse and compile times in hot-load scenarios ensure that loading times are smoother and faster. Some of the other capabilities featured in version 6.6 of Google’s V8 JavaScript Engine include:
- The compile times have been optimised significantly by moving out or depreciating the remaining functionality around AST numbering. A previous version of the V8 system process required postparsing stages that involved AST number – wherein the nodes in a syntax tree for JavaScript were numbered to give compilers a common reference point. However, this postprocessing feature began to evolve in the years to come, and a new pipeline introduced by Google eventually eliminated the need for AST numbering.
- More data protection has been added to prevent unwanted information leaks into WebAssembly and JavaScript code.
- Asynchronous and array performance has been improved significantly by Google developers.
If you’re interested in finding out the latest about the features of Google V8, or you want to download the system for yourself, you can head to the Google V8 website for access to the 6.6 beta. Developers with the active checkout capability will be able to use the git checkout feature to experiment with some of the features available within the new V8 Engine. Additionally, developers can also subscribe to the beta channel on Google to access new features when they roll out.