Backward and forward compatibility in Javascript specification about you-dont-know-js HOT 2 CLOSED

Please see my several comments in this thread: #1803

from you-dont-know-js.

The description provided in the Babel official documentation and the statement in the book are not necessarily contradictory but may appear so due to different perspectives and contexts.

Babel is primarily known for converting ECMAScript 2015+ (ES6+) code into a backwards-compatible version of JavaScript. This means it takes modern JavaScript code, which might use the latest language features that are not supported by older browsers or JavaScript engines, and transforms it into equivalent code that is compatible with those older environments. In this sense, Babel helps developers write code using the latest syntax and features without worrying about whether it will work on older platforms.

However, the statement in the book refers to the broader concept of forward compatibility. In the book's context, "forward-compatible" means writing code using the latest syntax forms while trusting that the tools, such as Babel, will handle converting it into a version that will work on older engines. This perspective encourages developers to embrace modern JavaScript and not limit their code to older syntax just for compatibility reasons. Instead, they can use modern features, knowing that tools like Babel can produce a version that will work even in older environments.

In essence, Babel's primary goal is to provide backwards compatibility, but it can be seen as enabling forward compatibility as well. By writing code using modern syntax, you're being forward-compatible in the sense that your code is ready for future JavaScript engines and environments while still being transformed to work on older ones.

So, to sum up, Babel's main purpose is to produce a backward-compatible version of JavaScript, but it facilitates forward compatibility by allowing developers to write modern code that can be transformed for older environments.

from you-dont-know-js.