Why do people use colons in javascript function declarations.

[zulubob]

Hi. I've been looking at the table sorting script available at http://www.workingwith.me.uk/article..._table_sorting and have a few questions about the coding style.

I would like to know what is the difference between

init : function() {
		// do stuff	
		
	},

and

function init () {
		// do stuff	
		
		
	}

Is this somthing to do with labels. What are the advantages and disadvantages of the two approaches?

I look forward to learning from your answers.

[Kravvitz]

It's because {} is an object literal and those functions are being defined as properties of the object.

Here's an example:

var myObject = {
  foo : 'bar',
  talk : function() {
   alert('hello world')
  }
}
myObject.talk();
alert(myObject.foo);

The advantage of using the object literal is that you can keep a bunch of variables and functions grouped together and keep them out of the global scope which helps avoid naming conflicts.

[zulubob]

thanks

[iulian]

It's called JSON.

[zulubob]

Sorry to bother you again, I've hit another problem what is the difference between

bold.onclick = this.revealMore;

and

bold.onclick = this.revealMore();

[DougBTX]

Sorry to bother you again, I've hit another problem what is the difference between

One assigns the function to a variable, one calls the function and assigns the return value to a variable. Try this:

function foo() {
  return "bar";
}

var alpha = foo();
var beta = foo;

alert(alpha);
alert(beta);

You'll see the returned string "bar" in the first alert box, and a string representation of the function object in the second alert box.

The beauty of this, is that if you assign a funciton to a variable, you can treat that variable as a function. So following on from the above,

alert(beta());

Which shows a message box with "bar" in it, because you've called the function by putting () after it.

In fact, there is very little difference between these two code snippets:

var foo = function() {};

function foo() {}

Douglas

[DougBTX]

It's called JSON.

Not really, JSON object's can't contain functions. Also, you have to quote the object keys, like so:

{
    "name": "steve",
    "age" : 29
}

Douglas

[iulian]

Yes, DougBTX, you're right .

In fact is very clear also from the first paragraph of the JSON definition:

JSON (JavaScript Object Notation) is a lightweight data-interchange format. [...] It is based on a subset of the JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999.

[DougBTX]

In fact is very clear also from the first paragraph of the JSON definition

Why'd you post it then?? Meh, doesn't matter.

[iulian]

I was confusing JSON and literal objects. Now it's clear what's the difference between them.