Get name as String from a Javascript function reference?

Question

I want to do the opposite of Get JavaScript function-object from its name as a string?

That is, given:

function foo()
{}

function bar(callback)
{
           


        

Answer 1

for me, with just a little modification (adding \ before parent), this work:

if (Function.prototype.name === undefined){
  // Add a custom property to all function values
  // that actually invokes a method to get the value
  Object.defineProperty(Function.prototype,'name',{
    get:function(){
      return /function ([^\(]*)/.exec( this+"" )[1];
    }
  });
}

Answer 2

var name = callback.name;

MDN:

The name property returns the name of a function, or an empty string for anonymous functions:

Live DEMO

Answer 3

try to access the .name property:

callback.name 

Answer 4

If you can't use myFunction.name then you can:

// Add a new method available on all function values
Function.prototype.getName = function(){
  // Find zero or more non-paren chars after the function start
  return /function ([^(]*)/.exec( this+"" )[1];
};

Or for modern browsers that don't support the name property (do they exist?) add it directly:

if (Function.prototype.name === undefined){
  // Add a custom property to all function values
  // that actually invokes a method to get the value
  Object.defineProperty(Function.prototype,'name',{
    get:function(){
      return /function ([^(]*)/.exec( this+"" )[1];
    }
  });
}

Answer 5

var x = function fooBar(){};
console.log(x.name);
// "fooBar"

Answer 6

You can extract the object and function name with:

function getFunctionName()
{
    return (new Error()).stack.split('\n')[2].split(' ')[5];
}

For example:

function MyObject()
{
}

MyObject.prototype.hi = function hi()
{
    console.log(getFunctionName());
};

var myObject = new MyObject();
myObject.hi(); // outputs "MyObject.hi"