Get anonymous function name

Question

How to get the the variable name from within a function in this example:

// it should return A
var A = function(){ console.log(this.name); } 

Is there something like this?

Answer 1

No, there is nothing like that in Javascript. That function is anonymous, so it has no name, and what you want is ambiguous because the function could just as easily have any number of variables referencing it like:

var a, b, c, d;
a = b = function(){ console.log(this.name); };
c = b;
d = c;
a = b = 5;
// a and b no longer refer to the function, but c and d both do

What is it you are actually trying to accomplish? I'm sure there is another way to achieve it.

Answer 2

I know this is an old thread, but still in search results. so just for reference:

a solution could simply be using the stacktrace.

var stack = new Error().stack;

use trim and split to get to the desired values.

Answer 3

It is possible in recent versions of Chrome and Firefox as follows. I only recommend this for debugging purposes (e.g. javascript tracing in non-production)

var myNameInChrome = /.*Object\.(.*)\s\(/.exec(new Error().stack)[0];
var myNameInFF = new Error().stack.split("@")[0];

Answer 4

That function is anonymous; it has no name. You could, however, give it a name:

var A = function a() {};

Then its name is accessible via Function.name:

var A = function a() {};
A.name
> 'a'