Develop Reference

How to let callee know who is the caller [duplicate]

function main()
{
Hello();
}
function Hello()
{
// How do you find out the caller function is 'main'?
}
Is there a way to find out the call stack?

Note that this solution is deprecated and should no longer be used according to MDN documentation
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/caller
function Hello()
{
alert("caller is " + Hello.caller);
}
Note that this feature is non-standard, from Function.caller:
Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
The following is the old answer from 2008, which is no longer supported in modern Javascript:
function Hello()
{
alert("caller is " + arguments.callee.caller.toString());
}

StackTrace
You can find the entire stack trace using browser specific code. The good thing is someone already made it; here is the project code on GitHub.
But not all the news is good:
It is really slow to get the stack trace so be careful (read this for more).
You will need to define function names for the stack trace to be legible. Because if you have code like this:
var Klass = function kls() {
this.Hello = function() { alert(printStackTrace().join('\n\n')); };
}
new Klass().Hello();
Google Chrome will alert ... kls.Hello ( ... but most browsers will expect a function name just after the keyword function and will treat it as an anonymous function. An not even Chrome will be able to use the Klass name if you don't give the name kls to the function.
And by the way, you can pass to the function printStackTrace the option {guess: true} but I didn't find any real improvement by doing that.
Not all browsers give you the same information. That is, parameters, code column, etc.
Caller Function Name
By the way, if you only want the name of the caller function (in most browsers, but not IE) you can use:
arguments.callee.caller.name
But note that this name will be the one after the function keyword. I found no way (even on Google Chrome) to get more than that without getting the code of the whole function.
Caller Function Code
And summarizing the rest of the best answers (by Pablo Cabrera, nourdine, and Greg Hewgill). The only cross-browser and really safe thing you can use is:
arguments.callee.caller.toString();
Which will show the code of the caller function. Sadly, that is not enough for me, and that is why I give you tips for the StackTrace and the caller function Name (although they are not cross-browser).

I usually use (new Error()).stack in Chrome.
The nice thing is that this also gives you the line numbers where the caller called the function. The downside is that it limits the length of the stack to 10, which is why I came to this page in the first place.
(I'm using this to collect callstacks in a low-level constructor during execution, to view and debug later, so setting a breakpoint isn't of use since it will be hit thousands of times)

I know you mentioned "in Javascript", but if the purpose is debugging, I think it's easier to just use your browser's developer tools. This is how it looks in Chrome:
Just drop the debugger where you want to investigate the stack.

In both ES6 and Strict mode, use the following to get the Caller function
console.log((new Error()).stack.split("\n")[2].trim().split(" ")[1])
Please note that, the above line will throw an exception if there is no caller or no previous stack. Use accordingly.
To get callee (the current function name), use:
console.log((new Error()).stack.split("\n")[1].trim().split(" ")[1])

If you are not going to run it in IE < 11 then console.trace() would suit.
function main() {
Hello();
}
function Hello() {
console.trace()
}
main()
// Hello # VM261:9
// main # VM261:4

You can get the full stacktrace:
arguments.callee.caller
arguments.callee.caller.caller
arguments.callee.caller.caller.caller
Until caller is null.
Note: it cause an infinite loop on recursive functions.

To recap (and make it clearer) ...
this code:
function Hello() {
alert("caller is " + arguments.callee.caller.toString());
}
is equivalent to this:
function Hello() {
alert("caller is " + Hello.caller.toString());
}
Clearly the first bit is more portable, since you can change the name of the function, say from "Hello" to "Ciao", and still get the whole thing to work.
In the latter, in case you decide to refactor the name of the invoked function (Hello), you would have to change all its occurrences :(

I would do this:
function Hello() {
console.trace();
}

You can use Function.Caller to get the calling function. The old method using argument.caller is considered obsolete.
The following code illustrates its use:
function Hello() { return Hello.caller;}
Hello2 = function NamedFunc() { return NamedFunc.caller; };
function main()
{
Hello(); //both return main()
Hello2();
}
Notes about obsolete argument.caller: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/arguments/caller
Be aware Function.caller is non-standard: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/caller

Looks like this is quite a solved question but I recently found out that callee is not allowed in 'strict mode' so for my own use I wrote a class that will get the path from where it is called. It's part of a small helper lib and if you want to use the code standalone change the offset used to return the stack trace of the caller (use 1 instead of 2)
function ScriptPath() {
var scriptPath = '';
try {
//Throw an error to generate a stack trace
throw new Error();
}
catch(e) {
//Split the stack trace into each line
var stackLines = e.stack.split('\n');
var callerIndex = 0;
//Now walk though each line until we find a path reference
for(var i in stackLines){
if(!stackLines[i].match(/http[s]?:\/\//)) continue;
//We skipped all the lines with out an http so we now have a script reference
//This one is the class constructor, the next is the getScriptPath() call
//The one after that is the user code requesting the path info (so offset by 2)
callerIndex = Number(i) + 2;
break;
}
//Now parse the string for each section we want to return
pathParts = stackLines[callerIndex].match(/((http[s]?:\/\/.+\/)([^\/]+\.js)):/);
}
this.fullPath = function() {
return pathParts[1];
};
this.path = function() {
return pathParts[2];
};
this.file = function() {
return pathParts[3];
};
this.fileNoExt = function() {
var parts = this.file().split('.');
parts.length = parts.length != 1 ? parts.length - 1 : 1;
return parts.join('.');
};
}

heystewart's answer and JiarongWu's answer both mentioned that the Error object has access to the stack.
Here's an example:
function main() {
Hello();
}
function Hello() {
try {
throw new Error();
} catch (err) {
let stack = err.stack;
// N.B. stack === "Error\n at Hello ...\n at main ... \n...."
let m = stack.match(/.*?Hello.*?\n(.*?)\n/);
if (m) {
let caller_name = m[1];
console.log("Caller is:", caller_name);
}
}
}
main();
Different browsers shows the stack in different string formats:
Safari : Caller is: main#https://stacksnippets.net/js:14:8
Firefox : Caller is: main#https://stacksnippets.net/js:14:3
Chrome : Caller is: at main (https://stacksnippets.net/js:14:3)
IE Edge : Caller is: at main (https://stacksnippets.net/js:14:3)
IE : Caller is: at main (https://stacksnippets.net/js:14:3)
Most browsers will set the stack with var stack = (new Error()).stack. In Internet Explorer the stack will be undefined - you have to throw a real exception to retrieve the stack.
Conclusion: It's possible to determine "main" is the caller to "Hello" using the stack in the Error object. In fact it will work in cases where the callee / caller approach doesn't work. It will also show you context, i.e. source file and line number. However effort is required to make the solution cross platform.

function Hello() {
alert(Hello.caller);
}

It's safer to use *arguments.callee.caller since arguments.caller is deprecated...

2018 Update
caller is forbidden in strict mode. Here is an alternative using the (non-standard) Error stack.
The following function seems to do the job in Firefox 52 and Chrome 61-71 though its implementation makes a lot of assumptions about the logging format of the two browsers and should be used with caution, given that it throws an exception and possibly executes two regex matchings before being done.
'use strict';
const fnNameMatcher = /([^(]+)#|at ([^(]+) \(/;
function fnName(str) {
const regexResult = fnNameMatcher.exec(str);
return regexResult[1] || regexResult[2];
}
function log(...messages) {
const logLines = (new Error().stack).split('\n');
const callerName = fnName(logLines[1]);
if (callerName !== null) {
if (callerName !== 'log') {
console.log(callerName, 'called log with:', ...messages);
} else {
console.log(fnName(logLines[2]), 'called log with:', ...messages);
}
} else {
console.log(...messages);
}
}
function foo() {
log('hi', 'there');
}
(function main() {
foo();
}());

Try accessing this:
arguments.callee.caller.name

Just console log your error stack. You can then know how are you being called
const hello = () => {
console.log(new Error('I was called').stack)
}
const sello = () => {
hello()
}
sello()

I wanted to add my fiddle here for this:
http://jsfiddle.net/bladnman/EhUm3/
I tested this is chrome, safari and IE (10 and 8). Works fine. There is only 1 function that matters, so if you get scared by the big fiddle, read below.
Note:
There is a fair amount of my own "boilerplate" in this fiddle. You can remove all of that and use split's if you like. It's just an ultra-safe" set of functions I've come to rely on.
There is also a "JSFiddle" template in there that I use for many fiddles to simply quick fiddling.

If you just want the function name and not the code, and want a browser-independent solution, use the following:
var callerFunction = arguments.callee.caller.toString().match(/function ([^\(]+)/)[1];
Note that the above will return an error if there is no caller function as there is no [1] element in the array. To work around, use the below:
var callerFunction = (arguments.callee.caller.toString().match(/function ([^\(]+)/) === null) ? 'Document Object Model': arguments.callee.caller.toString().match(/function ([^\(]+)/)[1], arguments.callee.toString().match(/function ([^\(]+)/)[1]);

Here, everything but the functionname is stripped from caller.toString(), with RegExp.
<!DOCTYPE html>
<meta charset="UTF-8">
<title>Show the callers name</title><!-- This validates as html5! -->
<script>
main();
function main() { Hello(); }
function Hello(){
var name = Hello.caller.toString().replace(/\s\([^#]+$|^[^\s]+\s/g,'');
name = name.replace(/\s/g,'');
if ( typeof window[name] !== 'function' )
alert ("sorry, the type of "+name+" is "+ typeof window[name]);
else
alert ("The name of the "+typeof window[name]+" that called is "+name);
}
</script>

Just want to let you know that on PhoneGap/Android the name doesnt seem to be working. But arguments.callee.caller.toString() will do the trick.

here is a function to get full stacktrace:
function stacktrace() {
var f = stacktrace;
var stack = 'Stack trace:';
while (f) {
stack += '\n' + f.name;
f = f.caller;
}
return stack;
}

Note you can't use Function.caller in Node.js, use caller-id package instead. For example:
var callerId = require('caller-id');
function foo() {
bar();
}
function bar() {
var caller = callerId.getData();
/*
caller = {
typeName: 'Object',
functionName: 'foo',
filePath: '/path/of/this/file.js',
lineNumber: 5,
topLevelFlag: true,
nativeFlag: false,
evalFlag: false
}
*/
}

Works great for me, and you can chose how much you want to go back in the functions:
function getCaller(functionBack= 0) {
const back = functionBack * 2;
const stack = new Error().stack.split('at ');
const stackIndex = stack[3 + back].includes('C:') ? (3 + back) : (4 + back);
const isAsync = stack[stackIndex].includes('async');
let result;
if (isAsync)
result = stack[stackIndex].split(' ')[1].split(' ')[0];
else
result = stack[stackIndex].split(' ')[0];
return result;
}

I could use these in 2021 and get the stack which starts from the caller function :
1. console.trace();
2. console.log((new Error).stack)
// do the same as #2 just with better view
3. console.log((new Error).stack.split("\n"))

Try the following code:
function getStackTrace(){
var f = arguments.callee;
var ret = [];
var item = {};
var iter = 0;
while ( f = f.caller ){
// Initialize
item = {
name: f.name || null,
args: [], // Empty array = no arguments passed
callback: f
};
// Function arguments
if ( f.arguments ){
for ( iter = 0; iter<f.arguments.length; iter++ ){
item.args[iter] = f.arguments[iter];
}
} else {
item.args = null; // null = argument listing not supported
}
ret.push( item );
}
return ret;
}
Worked for me in Firefox-21 and Chromium-25.

Another way around this problem is to simply pass the name of the calling function as a parameter.
For example:
function reformatString(string, callerName) {
if (callerName === "uid") {
string = string.toUpperCase();
}
return string;
}
Now, you could call the function like this:
function uid(){
var myString = "apples";
reformatString(myString, function.name);
}
My example uses a hard coded check of the function name, but you could easily use a switch statement or some other logic to do what you want there.

As far as I know, we have 2 way for this from given sources like this-
arguments.caller
function whoCalled()
{
if (arguments.caller == null)
console.log('I was called from the global scope.');
else
console.log(arguments.caller + ' called me!');
}
Function.caller
function myFunc()
{
if (myFunc.caller == null) {
return 'The function was called from the top!';
}
else
{
return 'This function\'s caller was ' + myFunc.caller;
}
}
Think u have your answer :).

Why all of the solutions above look like a rocket science. Meanwhile, it should not be more complicated than this snippet. All credits to this guy
How do you find out the caller function in JavaScript?
var stackTrace = function() {
var calls = [];
var caller = arguments.callee.caller;
for (var k = 0; k < 10; k++) {
if (caller) {
calls.push(caller);
caller = caller.caller;
}
}
return calls;
};
// when I call this inside specific method I see list of references to source method, obviously, I can add toString() to each call to see only function's content
// [function(), function(data), function(res), function(l), function(a, c), x(a, b, c, d), function(c, e)]

I think the following code piece may be helpful:
window.fnPureLog = function(sStatement, anyVariable) {
if (arguments.length < 1) {
throw new Error('Arguments sStatement and anyVariable are expected');
}
if (typeof sStatement !== 'string') {
throw new Error('The type of sStatement is not match, please use string');
}
var oCallStackTrack = new Error();
console.log(oCallStackTrack.stack.replace('Error', 'Call Stack:'), '\n' + sStatement + ':', anyVariable);
}
Execute the code:
window.fnPureLog = function(sStatement, anyVariable) {
if (arguments.length < 1) {
throw new Error('Arguments sStatement and anyVariable are expected');
}
if (typeof sStatement !== 'string') {
throw new Error('The type of sStatement is not match, please use string');
}
var oCallStackTrack = new Error();
console.log(oCallStackTrack.stack.replace('Error', 'Call Stack:'), '\n' + sStatement + ':', anyVariable);
}
function fnBsnCallStack1() {
fnPureLog('Stock Count', 100)
}
function fnBsnCallStack2() {
fnBsnCallStack1()
}
fnBsnCallStack2();
The log looks like this:
Call Stack:
at window.fnPureLog (<anonymous>:8:27)
at fnBsnCallStack1 (<anonymous>:13:5)
at fnBsnCallStack2 (<anonymous>:17:5)
at <anonymous>:20:1
Stock Count: 100

why does setting `this.property` in a function in a class make a new property but getting `this.property` uses the class property? [duplicate]

This question already has answers here:
How to access the correct `this` inside a callback
(13 answers)
Closed 7 years ago.
I have a class in javascript with a property (is_initialized) and a function (isInitialized).
Class definition :
function Test()
{
this.is_initialized = { obj: { isInitialized: 'notyet' } };
this.isInitialized = function( ref )
{
if ( !ref.obj )
{
console.log( 'now: ' + JSON.stringify( this.is_initialized ) );
/*line 9*/ this.is_initialized.obj.isInitialized = ref.isInitialized.toString();
console.log( ref );
}
else {
bluetoothle.isInitialized( this.isInitialized );
/*line 14*/ ref.obj = this.is_initialized.obj;
}
};
}
bluetoothle.isInitialized is a function in a cordova plugin (no knowledge of cordova is required for answering this question), it returns an object { isInitialized : true/false } and will pass the first if-statement whilst my call to isInitialized() will execute the else.
Question :
Why does this.is_initialized on line 9 create a new property inside the function isInitialized while this.is_initialized on line 14 uses the property is_initialized in Test()?
Shouldn't it both use the property inside Test() or use a (new) variable inside isInitialized()?
And if it 'just' behaves like this, what can i do to deal with it?
Code i ran :
var t = new Test();
var r = {obj:{isInitialized:'nope'}};
t.isInitialized(r);
// console.log( 'now: ' + JSON.stringify( this.is_initialized ) ); on line 8:
// now: {"obj":{"isInitialized":"false"}}
// console.log( ref ); on line 10:
// Object {isInitialized: false}
console.log(JSON.stringify(r));
// {"obj":{"isInitialized":"notyet"}}
console.log(JSON.stringify(t));
// {"is_initialized":{"obj":{"isInitialized":"notyet"}}}
What just happened is this:
i made a new instance of Test() and named it t.
i made an object with matching structure of is_initialized in Test() but with a different value.
i called the function with r as parameter.
code in the else executes.
asynchronous function with isInitialized as callback is called.
the function created a reference between the existing is_initialized and r.
the async function calls isInitialized and executes the code in the if.
it logs the current value of this.is_initialized on line 8, somehow it gets this.is_initialized after line 9 is executed.
line 9 executes, creating a new variable named is_initialized inside isInitialized() while i want it to set is_initialized in Test() and not create a new variable that dies when the function is done executing.
it logs the object that was put into this.is_initialized.obj.isInitialized.
i log r and see that it contains the initial value of Test.is_initialized.
i log t and see that is_initialized's value is still initial.
Info :
If you want to test it yourself to answer my question of the why? and the how do i deal with it? but need some code for bluetoothle.isInitialized just use this:
var bluetoothle = {isInitialized:function(){setTimeout(function(){func({isInitialized:false});},20);}};
// to execute:
bluetoothle.isInitialized(/*callbackfunction*/);
I would like to thank you for reading this long question.

You're in a function. Inside a function (unless it's declared as Test.prototype.isInitialized), the scoping rules for 'this' are different. This is one of the gotchas that ES6 aims to eliminate. (If you added "use strict"; at the top of the function most browsers would tell you this.)
Declare var self = this in Test and use self inside your interior function and you should get the result you want. #squint has pretty much already said this.

calling a javascript function from a string passed to the function

i have seen multiple questions of a similar nature on here, yet none would work for the specific thing that i have (im using node.js). so for example take this code here.
function command_call(message, socket) {
if (message.length > 1){
var func = message[0];
var string = message.slice(1);
var string = string.join(' ')}
else{
var func = message[0];
var string = '';};
if(func[0] == '$') {
(eval(func.slice(1)))(string, socket);};
};
function say(string, socket){
socket.write(string)};
if the message passed in to the command_call were to be "$say hi" the function say would be called and return "hi". this works just fine however, if the function that was put to the eval does not exist, it crashes. for instance if the message passed to the command_call were to be "$example blah" it would try to eval "example". basically i need it to check if the function exists before it evals the function. and YES i want to use eval, unless there is a better way to do it in node. and again, this is in node.js

You should make an object of functions and use indexer notation:
var methods = {
$say: function() { ... }
};
if (!methods.hasOwnProperty(func))
// uh oh
else
methods[func]();

Force missing parameters in JavaScript

When you call a function in JavaScript and you miss to pass some parameter, nothing happens.
This makes the code harder to debug, so I would like to change that behavior.
I've seen
How best to determine if an argument is not sent to the JavaScript function
but I want a solution with a constant number of typed lines of code; not typing extra code for each function.
I've thought about automatically prefixing the code of all functions with that code, by modifying the constructor of the ("first-class") Function object.
Inspired by
Changing constructor in JavaScript
I've first tested whether I can change the constructor of the Function object, like this:
function Function2 () {
this.color = "white";
}
Function.prototype = new Function2();
f = new Function();
alert(f.color);
But it alerts "undefined" instead of "white", so it is not working, so I've don't further explored this technique.
Do you know any solution for this problem at any level? Hacking the guts of JavaScript would be OK but any other practical tip on how to find missing arguments would be OK as well.

If a function of yours requires certain arguments to be passed, you should check for those arguments specifically as part of the validation of the function.
Extending the Function object is not the best idea because many libraries rely on the behavior of defaulting arguments that are not passed (such as jQuery not passing anything to it's scoped undefined variable).
Two approaches I tend to use:
1) an argument is required for the function to work
var foo = function (requiredParam) {
if (typeof requiredParam === 'undefined') {
throw new Error('You must pass requiredParam to function Foo!');
}
// solve world hunger here
};
2) an argument not passed but can be defaulted to something (uses jQuery)
var foo = function (argumentObject) {
argumentObject = $.extend({
someArgument1: 'defaultValue1',
someArgument2: 'defaultValue2'
}, argumentObject || {});
// save the world from alien invaders here
};

As others have said, there are many reasons not to do this, but I know of a couple of ways, so I'll tell you how! For science!
This is the first, stolen from Gaby, give him an upvote! Here's a rough overview of how it works:
//example function
function thing(a, b, c) {
}
var functionPool = {} // create a variable to hold the original versions of the functions
for( var func in window ) // scan all items in window scope
{
if (typeof(window[func]) === 'function') // if item is a function
{
functionPool[func] = window[func]; // store the original to our global pool
(function(){ // create an closure to maintain function name
var functionName = func;
window[functionName] = function(){ // overwrite the function with our own version
var args = [].splice.call(arguments,0); // convert arguments to array
// do the logging before callling the method
if(functionPool[functionName].length > args.length)
throw "Not enough arguments for function " + functionName + " expected " + functionPool[functionName].length + " got " + args.length;
// call the original method but in the window scope, and return the results
return functionPool[functionName].apply(window, args );
// additional logging could take place here if we stored the return value ..
}
})();
}
}
thing(1,2 ,3); //fine
thing(1,2); //throws error
The second way:
Now there is another way to do this that I can't remember the details exactly, basically you overrride Function.prototype.call. But as it says in this question, this involves an infinite loop. So you need an untainted Function object to call, this is done by a trick of turning the variables into a string and then using eval to call the function in an untainted context! There's a really great snippet out the showing you how from the early days of the web, but alas I can't find it at the moment. There's a hack that's required to pass the variables properly and I think you may actually lose context, so it's pretty fragile.
Still, as stated, don't try and force javascript to do something against its nature, either trust your fellow programmers or supply defaults, as per all the other answers.

You can imitate something like Python’s decorators. This does require extra typing per function, though not extra lines.
function force(inner) {
return function() {
if (arguments.length === inner.length) {
return inner.apply(this, arguments);
} else {
throw "expected " + inner.length +
" arguments, got " + arguments.length;
}
}
}
var myFunc = force(function(foo, bar, baz) {
// ...
});
In general this sounds like a bad idea, because you’re basically messing with the language. Do you really forget to pass arguments that often?

You could use the decorator pattern. The following decorator allows you to specify minimum and maximum number of arguments that need to be passed and an optional error handler.
/* Wrap the function *f*, so that *error_callback* is called when the number
of passed arguments is not with range *nmin* to *nmax*. *error_callback*
may be ommited to make the wrapper just throw an error message.
The wrapped function is returned. */
function require_arguments(f, nmin, nmax, error_callback) {
if (!error_callback) {
error_callback = function(n, nmin, nmax) {
throw 'Expected arguments from ' + nmin + ' to ' + nmax + ' (' +
n + ' passed).';
}
}
function wrapper() {
var n_args = arguments.length;
console.log(n_args, nmin, nmax);
console.log((nmin <= 0) && (0 <= nmax));
if ((nmin <= n_args) && (n_args <= nmax)) {
return f.apply(this, arguments);
}
return error_callback(n_args, nmin, nmax);
}
for (e in f) {
wrapper[e] = f[e];
}
return wrapper;
}
var foo = require_arguments(function(a, b, c) {
/* .. */
}, 1, 3);
foo(1);
foo(1, 2);
foo(1, 2, 3);
foo(1, 2, 3, 4); // uncaught exception: Expected arguments from 1 to 3 (4 passed).
foo(); // uncaught exception: Expected arguments from 1 to 3 (0 passed).

How can I get the name of function inside a JavaScript function?

How is it possible to learn the name of function I am in?
The below code alerts 'Object'. But I need to know how to alert "Outer."
function Outer(){
alert(typeof this);
}

This will work:
function test() {
var z = arguments.callee.name;
console.log(z);
}

I think that you can do that :
var name = arguments.callee.toString();
For more information on this, take a look at this article.
function callTaker(a,b,c,d,e){
// arguments properties
console.log(arguments);
console.log(arguments.length);
console.log(arguments.callee);
console.log(arguments[1]);
// Function properties
console.log(callTaker.length);
console.log(callTaker.caller);
console.log(arguments.callee.caller);
console.log(arguments.callee.caller.caller);
console.log(callTaker.name);
console.log(callTaker.constructor);
}
function callMaker(){
callTaker("foo","bar",this,document);
}
function init(){
callMaker();
}

As of ES6, you can use Function.prototype.name. This has the added benefit of working with arrow functions, since they do not have their own arguments object.
function logFuncName() {
console.log(logFuncName.name);
}
const logFuncName2 = () => {
console.log(logFuncName2.name);
};

Took me a while to figure this out, so tried to make it very clear for rookies like me.
Approach 1 - arguments.callee.name
This approach used to work, but now in ES6 Strict Mode it will fail. Don't use Approach 1.
//approach 1 - don't use
let functionName = arguments.callee.name;
console.log(functionName);
Approach 2 - create a function and use caller.name
This approach works in the latest version of Javascript and will not fail in Strict Mode. Use Approach 2. There are 2 steps.
Step 1 - Create a function that uses caller.name to return the name of the function that called it. Add this function to your code:
function getFuncName() {
return getFuncName.caller.name
}
Step 2 - Call your function when you need the name of the function your code is currently in.
function iWantThisName() {
console.log(getFuncName())
}
iWantThisName()
// Logs: "iWantThisName"