If object.assign is built-in why using bable-plugin for it?

Question

I found this plugins in .babelrc file

"plugins": [
["transform-replace-object-assign", "object.assign"] ]

and as i know Object.assign() is built-in method in all modern browsers.

So why using it as plugins inside .babelrc?

Thanks.

Answer 1

It depends how you define "modern browsers". Object.assign isn't present in Internet Explorer, which accounts for about one in eight users at the time of writing.

Whatever the case, depending on the purpose of your website, you may wish to support all kinds of users using all kinds of browsers. Remember, many users are unable or unwilling to upgrade their browser for various reasons.

Answer 2

Object.assign is not supported in IE.

It's not about supporting modern browsers - but as many browsers as possible. That said, it's always a good idea to include babel and polyfills for older browsers so you can write in modern JS but still support the less modern browsers.