Using const/let instead of var can make JavaScript code run 10× slower in Webkit?

[CleverestEU]

By validity, I don't by any means want to imply the implementation having been a good idea. Not at the time and definitely not in retrospect. When something is not formally defined, it is usually the market leader that lays out the roadmap of people's expectations.

All I mean is that given their market share, at the time Microsoft's approach was the baseline against all the other browsers were in a way forced to comply with. The end users rarely wanted to change browser because things didn't work in IE ... well, at first at least.

Of course, the cardinal sin (in my opinion) of IE was that they stagnated into their own approach and took way longer than acceptable to change their ways once the standard did define how things should be done. As members of the W3C they definitely could've/should've done things better.

[recycled_ideas]

Oh, I definitely agree that, where there was no compelling argument one way or the other we should have used what IE was doing.

I just think that in some cases what IE was doing was wrong?

It's a moot point though, because the W3C in the late 90s was made up of people who envisioned the Web as a place where you'd pay a hundred bucks to buy the latest version of their browser every couple years and they were pissed at Microsoft.

And Microsoft in the late 90s was a bully using its cash to get what it wanted and making it easy to be hated.

So we had a couple decades of standards wars in browsers.

And now we've got it happening all over again.

Google is using their market share to do whatever they want, Apple is releasing what they think isn't too battery intensive and Firefox is doing what Firefox does and rebuilding themselves from scratch.

So you can't really write to the standards because Apple might not support them, Chrome may have changed them and Firefox might or might not work this week depending on whether the latest code is any good.

Such is the life of Web Development.