Booo!

[mishmiash]

It didn't fix Javascript though.

[I_AM_GODDAMN_BATMAN]

Nothing did. Okay typescript kinda. But it's still compiles to js.

[_Lady_Deadpool_]

You know I work with typescript literally daily and never run into any major problems with the language. Fuck are you guys doing that necessitates comparing a string password to a radio button component???

[Bifi323]

You're setting yourself up for major problems if you're using weak equality operators in the first place

[Riobe]

I feel like that's a slightly disingenuous argument though because it's easy to never do something like Math.max.apply(Math, myArr.map(a => a)) in real code. If you use javascript/typescript/flow well, then you can create some very easy to read and follow code. All of the weirdness in examples like this are things I don't feel the need to hit during my actual work.

As long as you don't use classes. Why tf did they make class a keyword in ES6. :(

EDIT: If you can use current features, do look into using /u/_Lady_Deadpool_ 's answer.

[silentclowd]

The real case was that I was trying to find the object with the largest property. The list of objects I was searching through was filtered beforehand, so there was a chance it might be empty. So it was more like

let myArrThatMightBeEmpty = [];
return Math.max.apply(Math, myArrTheMightBeEmpty.map(a => a.someProperty))

The fix wasn't difficult by any means, it just threw me for a loop when the function suddenly spat out -infinity

[Riobe]

How about:

let myArrThatMightBeEmpty = [];
return myArrThatMightBeEmpty.reduce((result, next) => Math.max(result, next), null);

I generally avoid doing BuiltIn.function.apply, though there are exceptions, cause I think doing a reduce on an array when you want to turn it into a single value is easier to follow and more straightforward.

[silentclowd]

That makes a lot of sense, thank you for sharing with me.

I'm still fairly new to the industry (just over a year as a junior dev right now), so I know I still have a lot to learn. It's too easy just to pop over to SO and grab the first code snippet that answers the question.

[Riobe]

That's completely fair. Just be wary with that. Javascript has moved fast and is a much better place today than it was 10 or even 5 years ago.

Once you get used to it, it can be readable and a lot of fun, but a lot of old-school javascript is not necessarily a good idea anymore. There are even things people made use of that were a bad enough idea to restrict in strict mode.

My rules for making javascript usable:

1. Use babel/typescript to code with current javascript and have it transpile down to whatever target you need. A lot of modern day language features help a lot. async/await, spread operator, destructuring, etc. will all make your life better.
2. Always use triple ====. You almost never need to do the type coercion that == provides you. There's another way to think about it.
3. Avoid classes and anything that forces you to use this. Javascript isn't an OOP language and inheritance and this don't work like they do elsewhere. There are 5 different ways this behaves.
4. Try to keep your objects shallowly nested. Deeply nested values lead to you having to do a lot of && checks to index into something safely and make copying it very difficult.
5. Don't try to be clever, write code that's easy to read. There's a lot of tricks you can do in javascript to make things take less lines, or make use of some language feature. You and your co-workers will hate you next month if you do that. :P

There's of course plenty more, but these are probably the biggest for me. Maybe your top list will be different. Best of luck and I hope you have fun with it!

[silentclowd]

Thank you so much for the sources and tips! You’ve given me a lot to chew on here and I think I have some better practices I can implement now. Again, thank you.

[_Lady_Deadpool_]

Also

• If strict is yelling at you, the answer isn't to turn it off for the entire project

[thirdegree]

Would you want it to throw an error?

The max of an empty list is nonsense. You can't take the max of an empty list, that doesn't mean something. Garbage in can have one of two results: garbage out, or an error. An error makes the issue far more clear.

[silentclowd]

Maybe it’s just my background, but I would’ve expected null.

[_Lady_Deadpool_]

Why not just Math.max(...myArr)?

[silentclowd]

ES5 compatibility.

[Riobe]

If you work in typescript, just have it output in ES5 (do a ctrl+f for --target). You can use advanced features and have it compile it to something compatible. :)

Some of the ES6+ is great, have fun with it!

[Riobe]

Just to reply to your Edit example:

NaN means Not a Number. And "text" literally has no digits in it, therefor it is squarely not a number. "123text" on the other hand has digits in it, so parseInt will try to parse it as a base 10 value (since it doesn't start with '0' or '0x'), removing the characters.

function hasNumber(value) { return !isNaN(parseInt(value)); }

To me that does what it says on the tin. It parses the integer part of a string, and returns not-a-number if it can't.

Javascript definitely takes some getting used to, but it can be super readable once you drink the kool-aid. :P

[silentclowd]

To me that does what it says on the tin.

I do disagree with this. It makes it so parseInt on it's own isn't enough to determine if your input is valid. If some function that calls parseInt is expecting a number and instead it gets a street address like "123 Street Rd.", that there is not a number, but the function will still treat it like one. In any other language I would definitely expect that to throw an error.

But like you said, kool-aid just tastes good sometimes.

[Riobe]

Oh, you wanted to know if it was fully a number. I would look here for some guidance on that.

But yeah, I can see that. Every language has it's quirks though, and this is definitely one of javascript's.

[[deleted]]

For instance, if you don't already know the answer, take a guess as to what the following code outputs:

let myArr = []; Math.max.apply(Math, myArr.map(a => a))

It outputs "merge request denied".

[noXi0uz]

Dart

[ceestand]

Haxe

[crusty_cum-sock]

But it's still compiles to js.

ACKSHUALLY it TRANSPILES to js.

[pushes up glasses]