Get the name of the anonymous variable that contains the function

Question

I have the functions

function getCallingFunctionName() {
    alert(arguments.callee.caller.name.toString();
}

var bob = function() {
    ...
    getCallingFunctionName();
}

When the code is run the value alerted is an empty string is returned. I need to return

bob

I CANNOT change the original functions (im dealing with a large project with thousands of functions etc.

var bob = function bob() {
    ...
    getCallingFunctionName();
}

Any one got any other ideas ? Its not critical to have but basically to help with debugging.

If an anonymous function has a name, it isn't anonymous is it? — Matt Burland, Jan 22 '14 at 17:51
I'm not exactly sure what problem you're trying to solve. But if you need an identifier, can't you simply add a local variable identifying the name of the function? — Harvey A. Ramer, Jan 22 '14 at 17:52
`arguments.callee.caller` is deprecated. See this: http://stackoverflow.com/questions/103598/why-was-the-arguments-callee-caller-property-deprecated-in-javascript/235760#235760 — Matt Burland, Jan 22 '14 at 17:54
okay guys thanks for your help, i was lookinf for something a shortcut, it doesnt appear possible, so ill do a longwinded version — Welsh King, Jan 22 '14 at 18:01

score 2 · Answer 1 · answered Jan 22 '14 at 18:02

What if you try to do something like this:

function getCallingFunctionName() {
    try {
        throw new Error();
    }
    catch(e) {
        console.log(e);
    }
}

var bob = function() {
    getCallingFunctionName();
}

It will give you something like this:

Error
    at getCallingFunctionName (<anonymous>:4:15)
    at bob (<anonymous>:12:5)
    at <anonymous>:2:1
    at Object.InjectedScript._evaluateOn (<anonymous>:581:39)
    at Object.InjectedScript._evaluateAndWrap (<anonymous>:540:52)
    at Object.InjectedScript.evaluate (<anonymous>:459:21)

which you can use for your purpose, i.e. to extract function name. The only sad thing is that IE supports Error.stack starting from version 10.

i love answers like this, there's always a 'way' – fanfare Jan 30 '23 at 05:47 — fanfare, Jan 30 '23 at 05:47

score 0 · Answer 2 · answered Jan 22 '14 at 18:14

Here is a way, that requires a little extra effort/code, but maybe it suits you:

var cache = {};

var bob = function () {
    getCallingFunctionName();
}

function getCallingFunctionName() {
    alert(cache[arguments.callee.caller.toString()]);
}

cache[bob.toString()] = "bob";

bob(); //bob

So you are basically caching the function string representation (which is the complete function body) and using it as a key for the actual function name. Afterwards you can access the name, using again only func.toString(). Of course, this requires that you don't have two functions who have the exact same body.

Get the name of the anonymous variable that contains the function

2 Answers2