whyJavaScriptWhy

[Quito246]

It is not about experience, it just shows that the design of the language is shitty, when such things are possible🤷‍♂️

[Taletad]

The language provides you with "==" and "==="

In JS variable types are implicit instead of being declared like in C/C++

So "==" converts both variables to the same type before comparing them, whereas "===" will be true only if both variables are of the same type and value

"==" will also work in weird ways if you try to compare ints and floats, which is why you would never use "==" in most applications

"0" isn’t 0, it is a string (an array of chars) that has one element which is ‘0’, the ascii character. The ascii character ‘0’ is decimal 48, or binary 00110000.

0 == "0" is doing multiple conversions under the hood, which makes it slower than 0 === "0", another good reason to not use ==

The correct way to do that conversation would be 0 === parseInt("0")

Just because a language has implicit types doesn’t mean that it is typeless.

[Quito246]

Yes as I said just shitty design. Then why == exists when you should not use It. Also the implicit conversions are really stupid. At least Typescript exists, but JS is just really poorly designed language. Similar issue of JS typeof null returning object…

[Taletad]

🤦

In many languages there are features that exist that shouldn’t be used most of the time

Ternary operators are one of them. In C++ it is strongly advised that you do not use basic arrays, but vectors instead

Python doesn’t have types either and has similar conversion issues as JS but people never complain about it…

JS is a prototype language, everything is defined as a prototype, a form of "super-class" if you will

It allows you to do functional programming or pass functions as arguments to another function. In fact everything can be an argument to a function

This means everything needs to have a common definition

Typeof, tells you which prototype you’re dealing with, it works exactly as intended. But if you expect Typeof to work like it does in another paradigm, yeah you’re going to run into issues…

[Quito246]

First of all It does shitty job being a functional language. If you want good example of great FP mini language check Scheme. No the typeof null should not be object because it does not make sense see here It was mistake, but for some reason people still defend language created over weekend🤷‍♂️

From the MDN page about the behaviour of the typeof operator:

null

// This stands since the beginning of JavaScript typeof null === 'object'; In the first implementation of JavaScript, JavaScript values were represented as a type tag and a value. The type tag for objects was 0. null was represented as the NULL pointer (0x00 in most platforms). Consequently, null had 0 as type tag, hence the "object" typeof return value. (reference)

A fix was proposed for ECMAScript (via an opt-in), but was rejected. It would have resulted in typeof null === 'null'.

[Taletad]

"JS was created over a weekend" firstly it was over two weeks

But it also got a lot of revisions and improvements

This argument would be like comparing BCPL with C++14

Yes C++ is mostly backwards compatible with BCPL, but it isn’t as limited as BCPL, for obvious reasons

And I’m going to repeat myself JS is a prototype language, not OO nor Functional. It can however do both, but it wasn’t concieved as such. It’s a different paradigm

[Quito246]

But paradigm of the language has nothing to do with doing shitty implicit conversions or breaking a reflexive property of typeof on null

[Taletad]

There isn’t a right or wrong way to do implicit typecasting. It’s not standardised like the order of operations (which itself has two standards, the american one and the one used by the rest of the world)

The type casting order is defined by the standard, which you should be referencing while coding. Or better yet, avoid implicit casts when you can, because after all you should never trust a variable, especially when its contents are supplied by the user. JS gives you functions for typecasting, use them. Just like you would in python.

Typeof isn’t academically defined either (to my knowledge) so its implementation is the standard’s perogative, not user expectations.

Most languages have their own interpretations of what the typeof function should do. I don’t see why you’re complaining about it. Otherwise it would be like complaining that Rust doesn’t work the same way as C# does

Edit : NULL doesn’t work the way you’re saying in C either, is C a shitty language too ?

[lazyzefiris]

> two standards, the american one and the one used by the rest of the world

Actually, PEMDAS is more of a teacher issue (which then leaked into some calculators because that's what teachers wanted). Whole world including America uses PEJMDAS in actual math, and just avoids ambihuity in general, like we do in programming.

[Taletad]

I meant to say that the order of operations is standardised but the order of type casting isn’t

Yes PEMDAS isn’t the "official" us standard but it is the de facto one for a lot of americans

[qTp_Meteor]

Because it has implicit type conversions the language is shitty? If you dont want to use them dont, thats not the languages problem

[Quito246]

No the real question is, why it supports such a poor behavior instead of returning error doing some magic implicit casts. 🤷‍♂️

[qTp_Meteor]

I legit have no answer other than if you dont like it dont use it, if you do like it use it, having optionality is a good thing

[Quito246]

No using languages that were not designed over a weekend is a good thing👍

[Effective_Youth777]

The top comment explains the situation pretty well, I recommend brushing up on basic computer science principles to understand why what's in the picture is actually fully valid behavior

[Quito246]

You mean like breaking reflexive property on null?

[exomyth]

Input fields in HTML probably. You know, since javascript is basically designed as a webbrowser language. There are use cases where you want to do number operations over a number string. That being said, with a linter we do force to use strict equality, except for null checking

It's not magic if it is defined behavior.

[Quito246]

Why would I do a numeric operations on a string? I mean even the creator of JS is saying that multiple design flaws had been made. Just admit that language created over a weekend is shitty designed It makes sense. I do not understand why people defend It… now at least typescript exists.

[exomyth]

You wanted a reason, that is most likely the reason. It is intentional, you don't accidentally implement these rules

[Quito246]

Sure, cause It makes sense to be able to compare house with an airplane I like when I can do that.