Except strict equality, that’s a JavaScript only problem. Imagine thinking "0" should be falsy in comparison due to string literal evaluation, but truthy with logical not applied based on non-empty string. Thus !"0"=="0" is true. They couldn’t just throw away == and start over nooooo let’s add === . Utter madness
Browser compatibility. Design flaws can’t easily be fixed like how other languages can just switch to a new major version and introduce breaking changes. ES must keep backwards compatibility so has had to do more additive changes than replacing behavior altogether so that older web pages pages don’t break.
Strict vs loose equality has gotten me so many times, but I can sort of see why they did it. The problem you mention with integers 0 & 1 is a major annoyance though. Like it is fairly common to check whether a variable is populated by using if (variable) {} - if the variable happens to be an integer, and that integer happens to be 0, loose quality will reflect that as false.
But on the other side, there have been plenty of occasions where I’m expecting a boolean to come from somewhere and instead the data is passed as a text string. “true” == true but “true” !== true
Lua does intrinsic evaluation of strings that i’d argue is not nearly as crazy. I get the value of it since half of interpreted languages it just churning through strings. But I also don’t recommend any large codebase ever use JS’s == or string coercion because it can go against expectations. This graph argues in JS’s favor but comparison is a little more crazy https://algassert.com/visualization/2014/03/27/Better-JS-Equality-Table.html
Except strict equality, that’s a JavaScript only problem. Imagine thinking
"0"
should be falsy in comparison due to string literal evaluation, but truthy with logical not applied based on non-empty string. Thus!"0"=="0"
is true. They couldn’t just throw away==
and start over nooooo let’s add===
. Utter madnessBrowser compatibility. Design flaws can’t easily be fixed like how other languages can just switch to a new major version and introduce breaking changes. ES must keep backwards compatibility so has had to do more additive changes than replacing behavior altogether so that older web pages pages don’t break.
Meanwhile google is about to break the internet with html drm
Strict vs loose equality has gotten me so many times, but I can sort of see why they did it. The problem you mention with integers 0 & 1 is a major annoyance though. Like it is fairly common to check whether a variable is populated by using if (variable) {} - if the variable happens to be an integer, and that integer happens to be 0, loose quality will reflect that as false.
But on the other side, there have been plenty of occasions where I’m expecting a boolean to come from somewhere and instead the data is passed as a text string. “true” == true but “true” !== true
Lua does intrinsic evaluation of strings that i’d argue is not nearly as crazy. I get the value of it since half of interpreted languages it just churning through strings. But I also don’t recommend any large codebase ever use JS’s == or string coercion because it can go against expectations. This graph argues in JS’s favor but comparison is a little more crazy https://algassert.com/visualization/2014/03/27/Better-JS-Equality-Table.html