Basic question about function() 1

[minli98]

Hi,

I see that some functions are written as:

variable = function(){

}

What does this mean? And how is it different from the conventional function?

Thank you.

Min

 

[theniteowl]

This means that the function is called and that function returns a value that is assigned to variable.

Like this:

var myvalue = myfunction();

function myfunction()
{
return true;
}

Very basic example of course. What happens is that the myfuntion function returns true so when you set myvalue you are setting it to the result of the myfunction function.



Paranoid? ME?? WHO WANTS TO KNOW????

 

[deputydoofy]

Or it could be a simple equation:
var sum = addFunction(5,3);

function addFunction(a,b)
{
return (a+b);
}

The variable, sum, would be 8.

http://mywebpages.comcast.net/doofymusic

 

[tsdragon]

Look at the OP's example more carefully. What it is doing is creating an "anonymous" function, and assigning the function itself to the variable, not the return value of the function. Here's a better example:

var something = function() {
  alert("anonymoun function");
  return "some return value";
}

If you execute the statement:
[tt] alert(something)'[/tt]
what will be displayed in the alert box is:
[tt] function() {
alert("anonymoun function");
return "some return value";
}[/tt]
however, if you execute the statement:
[tt] something();[/tt]
you will get the alert that says "anonymous function".

The variable becomes a reference to the anonymous function.


Tracy Dryden

Meddle not in the affairs of dragons,
For you are crunchy, and good with mustard.

 

[minli98]

Sorry I need to clarify my question:

The conventional function that I know of has the format of

returnVar = function functionName(){

}

But I have seen declaration of functions without name, such as

returnVar = function(){

}

Does this mean that the function will automatically be run?

And then I am also baffled by lines like the following. This is from

http://www.dynamicdrive.com/dynamicindex1/anylink.js

(function dropdownmenu).

dropmenuobj.onmouseout=ie5? function(){ dynamichide(event)} : function(event){ dynamichide(event)}

Since dynamichide(event) is already a declared function, why the need to put function() in front? And what's the difference between function() and function(event)?

Thank you once again.

Min

 

[minli98]

Thanks tsdragon for the explanation. It's much clearer now. Please ignore my previous follow-up. I posted it before I read your posting.

Thank you all!

Min

 

[deputydoofy]

Thanks, tsdragon. I also appreciate the explanation.

http://mywebpages.comcast.net/doofymusic