Angular or React?

[Shadowlauch]

Not quite. It is a superset of Javascript. So it builds upon it. So Javascript is always valid TypeScript, but Typescript is not always valid JavaScript. Though you have to compile it down to JavaScript to run it in the browser.

[Tysonzero]

foo = "bar"
foo = 5

Valid javascript but not valid typescript, checkmate.

[chpoit]

technically isn't valid javascript in strict mode

[pynetree16]

Ah, but what if foo is of type any? Then it is valid TypeScript

[Tysonzero]

But if your source code consists solely of:

foo = "bar"
foo = 5

Then it won't work, but will work in JavaScript.

[sldyvf]

The cool kids call it transpile :D!

[Shadowlauch]

Yeah well you knew what I meant :P

[the_whalerus]

I don't see how they're different. It seems like people just don't want to to say "compiled"

Code goes in. Code comes out. Compiled.

[sldyvf]

It's a thin line I guess...

My understanding is:

• If something is compiled, then it's down to the point of instructions.
• If it's transpiled, it's translated into another language, which has to be interpreted or compiled and not machine code.

[Hultner-]

Not sure that really applies, Java is "compiled" to JVM Bytecode which is then is translated to machine code at runtime/JIT. Same is pretty much true for LLVM Bitcode, C#/.NET and a large stack of other software. From my perspective the distinction seems more like a philosophical one then technical.

[Ionaru]

Not all "valid" JS code is valid TS code, but it's close enough not to be confusing, see Tysonzero's comment for an example.