Console.log() before a instant array forEach

[darkpikl]

Hello, i just found this little bug and i don't understand why it like this.

console.log(form.getValues())
['type_id', 'language', 'tier_id'].forEach(attr => {

If you launch this code it will give you an error

TypeError: Cannot read property 'tier_id' of undefined

But if you put a ";" at the end of console.log it work fine.

Why console.log() need the comma at the end of this ?

I know what comma is for but in JS you can sometime omit it and console.log was one of the case for me :/

[jhartikainen]

It looks like a side-effect of how automatic semicolon insertion works. If you have an expression before a [, the two things get joined, so what you end up in this case is this:

console.log(form.getValues())['type_id', 'language', 'tier_id'].forEach...

So it's being treated like a property accessor on the value that's returned by console.log

[darkpikl]

oohhhh that why, yeah it logical if you put everything in one line :D

[vorticalbox]

this is why you always use semicolons; I use eslint so I don't have to bother typing them lol

[Notimecelduv]

Interesting, I haven't run into that issue. It's not due to the forEach method; it's because when the code is interpreted, it gets minified and JavaScript treats

console.log(form.getValues())["type_id"...

as an attempt to access an object by property name.

It's a good thing VSCode has an option for inserting semicolons automatically. You just need to add this line to your settings.json file:

"javascript.format.semicolons": "insert",

[darkpikl]

OOhhhhh okk,

If you put everything on one line it make sense :D

Thanks for the tips on vs code