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' );

}

[Martin Honnen]

Maguila007 wrote:

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

function something() {

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

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/

[Matt Kruse]

On May 2, 10:28 am, Maguila007 <[e-mail]:

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

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

[Geoffrey Summerhayes]

On May 2, 12:28 pm, Maguila007 <[e-mail]:

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' );

}

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

[Maguila007]

On May 2, 2:16 pm, Geoffrey Summerhayes <[e-mail]:

On May 2, 12:28 pm, Maguila007 <[e-mail]:

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' );

}

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

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?

[Matt Kruse]

On May 2, 12:09 pm, Maguila007 <[e-mail]:

But I need to know "what is my name" inside the function, I do not
have a variable pointing to the function.

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

[Geoffrey Summerhayes]

On May 2, 2:09 pm, Maguila007 <[e-mail]:

On May 2, 2:16 pm, Geoffrey Summerhayes <[e-mail]:

On May 2, 12:28 pm, Maguila007 <[e-mail]:

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' );

}

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

But I need to know "what is my name" inside the function, I do not
have a variable pointing to the function.

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.

I tested the callee.name and it´s work great for my porpouse in
Mozilla.
Is there anything like that for IE and Opera?-

arguments.callee initially contains the function body being executed
(ref ECMA 262 '97)
You'll have to extract the function name from there.

----
Geoff