When use "use strict"

Hello...
First time coding in JS.

Cam across this: https://javascript.info/strict-mode
Does this mean that I always have to put

"use strict"

"use strict"

at the top, or only if there is old JS to be implemented along side new?
I'm writing new, fresh, lovelly JS-files, do I need it then?

The modern mode, "use strict"

b1mind•2/28/23, 6:24 PM

Its implied for you when you use JS modules right?

Å Marlon GOP•2/28/23, 6:24 PM

Not a fan of the, choose if you want, options ...

So, as a first timer in JS maybe I should use it since it says ?

b1mind•2/28/23, 6:24 PM

ESM*

b1mind•2/28/23, 6:25 PM

ECMAScript modules uses strict mode by default

Å Marlon GOP•2/28/23, 6:25 PM

But isn't that just for some parts of the script?

b1mind•2/28/23, 6:25 PM

It depends how you are importing and using it

b1mind•2/28/23, 6:27 PM

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

Å Marlon GOP•2/28/23, 6:28 PM

I'm on level 0 of JS, and this was one intro to it: https://javascript.info/strict-mode (Am also trying codecademy's intro to JS)
Bam! In the JS fundamentals ... So that makes me feel like I need to understand it now before I learn more.

I think the answer to this is I'm gonna ignore it for now.

The modern mode, "use strict"

Å Marlon GOP•2/28/23, 6:29 PM

And when I start making scripts to implement for web I'll annoy you again.

b1mind•2/28/23, 6:30 PM

Just don't write the old way and you can impose strict on yourself and never really worry about it

b1mind•2/28/23, 6:30 PM

Å Marlon GOP•2/28/23, 6:30 PM

I have no idea what the old way is.

b1mind•2/28/23, 6:30 PM

dont use or

var

var

for example. Always use or

ÅÅ Marlon G I have no idea what the old way is. 🤔

b1mind•2/28/23, 6:31 PM

You will following that it teaches you modern JS

Å Marlon GOP•2/28/23, 6:31 PM

Aha! That I know ... so "use strict" makes var into let, for example?

b1mind•2/28/23, 6:33 PM

It will make you declare it but not which type. So you can't do without a var/let/const

Å Marlon GOP•2/28/23, 6:35 PM

Haha!!! Yes, I also think this is nonsense for me right now. I just exploded my head over how totally illogical functions are written out. I'll battle with them for now.

Å Marlon GOP•2/28/23, 6:35 PM

b1mind•2/28/23, 6:36 PM

Yea my point was not to derail you to something else either, just pointing out later lots of the times you will be dealing with ESM so it will be auto strict mode, its good to know about but you wont really be writing that line in projects.

Å Marlon GOP•2/28/23, 6:38 PM

Summary: I will only write , and leave

"use strict"

"use strict"

for later.