obtain function name

Maguila007

Hi

Is there any way to obtain the name of the function, inside the
function which was called.

Ex:

function something() {

alert( "The name of the function you invoke is " ......should
says 'something' );

}

May 2 '07 #1

Martin Honnen

Maguila007 wrote:
arguments.callee
gives you the function itself, in some implementations (e.g. Mozilla
JavaScript) functions have a name property so doing
alert(arguments.callee.name);
should do, otherwise you have to call toString() on the function object
and parse out the function name.




--

Martin Honnen
http://JavaScript.FAQTs.com/

May 2 '07 #2

Matt Kruse

On May 2, 10:28 am, Maguila007 <leonemat...@gmail.comwrote: No, because think about it - a function doesn't even need to have a
name. Or it can be referenced by 5 different names. A function is just
an object, whereas the name is one of potentially many references to
the object.

var func1 = func2 = func3 = function() { alert("what is my name?"); };

(function(){ alert("I don't even have a name"); })();

In simple cases, using arguments.callee may work, but it's by no means
a robust or dependable solution.

Matt Kruse

May 2 '07 #3

Geoffrey Summerhayes

On May 2, 12:28 pm, Maguila007 <leonemat...@gmail.comwrote: Sort of..

function functionName(fn)
{
var name=/\W*function\s+([\w\$]+)\(/.exec(fn);
if(!name)return 'No name';
return name[1];
}

function foo(){alert(functionName(foo))}

Of course, it would be easier to write:

function foo(){alert('foo')}

and get the same effect.

Also

var bar=foo;
foo(); ->gives 'foo'
bar(); ->gives 'foo'

and

var foo=function(){alert(functionName(foo))};
var bar=foo;
foo(); -gives 'No name'
bar(); -gives 'No name'

----
Geoff

May 2 '07 #4

Maguila007

On May 2, 2:16 pm, Geoffrey Summerhayes <sumr...@gmail.comwrote:
But I need to know "what is my name" inside the function, I do not
have a variable pointing to the function.
I tested the callee.name and it´s work great for my porpouse in
Mozilla.
Is there anything like that for IE and Opera?

May 2 '07 #5

Matt Kruse

On May 2, 12:09 pm, Maguila007 <leonemat...@gmail.comwrote: You do, but you just don't realize it.
Functions don't have names. When you say:

function foo() { }

you are just creating a function object, and assigning a reference to
it by the name of 'foo'. The function object itself knows nothing
about 'foo' - it's just the name you as a programmer gave it so you
could refer to it.

That may be getting a little deeper than you really are interested in,
but in order to really answer the question you need to understand how
this stuff works and why you may never get a solution that you're
happy with.

Matt Kruse

May 2 '07 #6

Geoffrey Summerhayes

On May 2, 2:09 pm, Maguila007 <leonemat...@gmail.comwrote: Of course you do. To work it requires the function to be written in
the form 'function *name* () {} so using *name* inside automatically
refers to the function unless you override it with a variable
definition.
If you use an obfuscation program on it, it should alter both to the
same to be correct.
arguments.callee initially contains the function body being executed
(ref ECMA 262 '97)
You'll have to extract the function name from there.

----
Geoff

May 2 '07 #7