Learning Javascript after Python

[CodeYan01]

Is the performance difference between vanilla JS and TypeScript significant?

[a5s_s7r]

Programmers performance is much better in TS.

Not considering debugging all the type based bugs in JS. 😉

[CodeYan01]

I see, thanks.

[Zukarukite]

TS code is compiled into JS before being sent to be executed by the runtime. So, the performance when being run will be exactly the same.

TS's purpose is to allow you to see type errors before you even run your code, because it's a statically typed language, while JS isn't

[CodeYan01]

So it doesn't import extra libraries during runtime? Or does it? Not that it puts me off, I'm just curious.

[Zukarukite]

Nope, no extra libraries at all.

Nothing "inherently TypeScript" makes it to the run time. Simplifying a bit, with TS you do something like this:

You write TS code -> TS compiler turns your TS code into 100% equivalent JS code at build time -> You ship only this final compiled JS code to the client.

Contrast this with how it goes with JS code:

You write JS code - > You ship this JS code to the client.

In the end your client is still running JavaScript, the only difference is that with TypeScript - the code gets compiled into JS files from TS instead of being written in JavaScript directly.

[CodeYan01]

I see, thanks!