[charcircuit]

    if (array.at) {
      explode();
    }

Adding the at function would break the above code which depends on array.at being undefined.

[egeozcan]

They test a lot of websites before introducing new methods. Something somewhere may break but it's very unlikely and this pragmatic approach allows progress.

This is also why the language got Array.prorotype.flat instead of flatten (flatten was breaking an old version of a popular library called Mootools): https://developer.chrome.com/blog/smooshgate/

[spartanatreyu]

And extending javascript's built-in objects has been considered bad practice since at least 2007.

Before that point, browser environments were so different that you needed to write code per-browser. Those theoretical concerns didn't really matter since in-practice you were essentially coding the same app in different scripting languages.

[egeozcan]

> extending javascript's built-in objects has been considered bad practice since at least 2007

Totally. It's just extending the prototype that causes the problem though, not extending from (class myclass extends array). This causes a lot of confusion among new js devs so I underline this on every opportunity.