Question

I’m looking for an equivalent to PHP’s __FUNCTION__ in JavaScript, to allow me to get the name of the current function. For example:

function foo(){
    console.log(__FUNCTION__); // "foo" would be logged to the console
}

Is there a way to do this in JavaScript? Either with a magic variable similar to __FUNCTION__ or any other workaround? And, if there’s not a way to currently achieve this, is it planned?

Answer 1

You might get a reference to the currently executing function via the callee property of the arguments object. Notice that it is deprecated with ES5.1 strict mode.

From that, you can get the (non-standard) name of the function. Notice that this only works for function declarations and named function expressions (with the known bugs in IE), but not for anonymous functions as object properties:

var myObj = {
    method: function() { // unnamed!
        return arguments.callee.name || "anonymous";
    }
};
myObj.method(); // "anonymous"

I for myself use static strings in debugging / error statements, prepending the whole namespace(s) of the function to easily locate it in the code.