How can I get the string of a type in JavaScript/TypeScript?

Question

In C# you could do something like this :

string typeName = typeof(int).FullName;

And the value of typeName would be System.Int32. (Refer this question for reference).

So, my question is, how can I achieve the same thing in JavaScript or TypeScript?

Please note that I do not want to get the type name from an object, I only want to get it from a type just like the example code above.

i think it makes very little sense to want to do this in javascript, since ; a : Javascript is weakly typed (try doing `"1" == true`), and b : the only types javascript knows are fairly descriptive of what they are. why would you need those 6 or so types with a "strong" name? — Timothy Groote, Oct 26 '17 at 14:43
the only thing i can find that comes close to what you are asking is doing something like `typeof Number()`, which would output *"number"* (shocking, right?) — Timothy Groote, Oct 26 '17 at 14:49
(but don't do `typeof Number`, because that would return *"function"*) — Timothy Groote, Oct 26 '17 at 14:54
To be frank, I actually wanted to use this feature in TypeScript — Wong Jia Hau, Oct 27 '17 at 09:24

Tanmay · Answer 1 · 2017-10-26T14:53:51.080

1

In Javascript you can use

typeof variable_name

edited Oct 26 '17 at 14:53

answered Oct 26 '17 at 14:33

Tanmay

1

It's not a function, it's a keyword, so the parentheses aren't needed. – Tom Fenech Oct 26 '17 at 14:42
@Tom yes you are right so I have corrected the answer – Tanmay Oct 26 '17 at 14:53
@Tanmay Thanks for your answer but this is not the answer I want, as I already mentioned in the question that I don't want to get the type name from an object. I want to get it directly from the type itself. – Wong Jia Hau Oct 26 '17 at 15:29
@Wong Jia Hau In Javascript there is only one way to declaring variable ie. var variable_name; So using Javascript, it is not achievable what you are trying to. – Tanmay Oct 27 '17 at 10:20

score 0 · Accepted Answer · answered Oct 26 '17 at 15:25

0

I just found out that the type-name package in Node.js can solve this problem.

answered Oct 26 '17 at 15:25

Wong Jia Hau

Iwan Wijaya · Answer 3 · 2017-10-26T14:50:23.867

-2

var typeName = 5;

so you can put a simple alert in javascript.

an example like,

alert(typeof typeName);

just it.

edited Oct 26 '17 at 14:50

answered Oct 26 '17 at 14:34

Iwan Wijaya

this wouldn't work in javascript *or* typescript, and it makes no sense. – Timothy Groote Oct 26 '17 at 14:35
i already try many times bro, if just you want to know your variable type, just using typeof its the simpliest way. https://codepen.io/iwanWijaya/pen/eeOmmj?editors=1111 – Iwan Wijaya Oct 26 '17 at 14:41
i'm talking about the code you posted here. try running `var string typeName = 5` in a console, or in typescript, and it will tell you there is a syntax error. – Timothy Groote Oct 26 '17 at 14:44
my bad, i just forgot, just put away the string word. blame on me. – Iwan Wijaya Oct 26 '17 at 14:49
@IwanWijaya While you are improving your answer. Did you ever hear of `code tags`? Or the senses of explaining things? Take a look at [How do I write a good answer](https://stackoverflow.com/help/how-to-answer) for reference. – Clijsters Oct 26 '17 at 14:54

3 Answers3