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javascript function vs jquery namespace function, the difference?

How come a javascript function like this below...
function stars() {
var mOpacity = $('#area').css('opacity');
if (mOpacity = 1) {
$('#title').find('.stars').animate({"marginTop":"-170px",opacity:1}, 3000)
.animate({opacity: 0}, 400)
.animate({"marginTop":"60px",opacity:0},0, stars);
}
}
stars();
...breaks my browser when I try to do something like this....
$.stars = function() {
var mOpacity = $('#area').css('opacity');
if (mOpacity = 1) {
$('#title').find('.stars').animate({"marginTop":"-170px",opacity:1}, 3000)
.animate({opacity: 0}, 400)
.animate({"marginTop":"60px",opacity:0},0, $.stars());
}
}
$.stars();
What is the lesson here between the 2 styles of functions?
Thanks
Ok based on everyones feedback to see more code, here is a full gimplse of the code on my .js file...
function mIntro() {
/********PRE-GAME ANIMATION*********/
$('#area').css({'opacity':0}).delay(1000).animate({opacity:1},300);
$('#title').find('.age').css({'opacity':0}).delay(2000).animate({opacity:1}, 3000);
function stars() {
var mOpacity = $('#area').css('opacity');
if (mOpacity = 1) {
$('#title').find('.stars').animate({"marginTop":"-170px",opacity:1}, 3000)
.animate({opacity: 0}, 400)
.animate({"marginTop":"60px",opacity:0},0, stars);
}
}
stars();
}
$(function() {
mIntro();
});
I have jquery connected to this .js page and I just can't understand why stars has to be in-cased in a traditional javascript function and not flexibile for a jquery namespace function. I bet it has something to do with the animate tag that re-calls stars, but I am not sure...
Thanks or any advice!!!

You're inadvertently calling it in the second snippet:
.animate(..., $.stars());
You should code it the same way: pass the function, not the result of calling it:
Function: stars $.stars
Result of calling: stars() $.stars()

The difference is that your first example is contained directly within the window object whereas the second example is contained in the jQuery ($) object (note that the $ object is then contained within the window object). As far as why it breaks when you attempt to use the jQuery namespace, I cant say without seeing all of your code, however $ is probably not defined.

JQuery can't find variable from separate javascript file

I am using the cakephp framework and I created 2 separate javascript files and placed them into my webroot/js folder. The first javascript file contains modal dialog variables that contain the settings for the dialog boxes. The second javascript file contains other click event handlers that post data to an action and then open up the dialog.
The problem I am having is that the second file calls a variable from the first file using
$variablename and I get an error saying varaibleName is not defined.
Some code is below to show you what I mean.
From the first file:
var $editSel = $("#editSel_dialog").dialog(
{
autoOpen: false,
height: 530,
width: 800,
resizable: true,
modal: true,
buttons:
{
"Cancel": function()
{
$(this).dialog("close");
}
}
});
From the second file:
$('.neweditSel_dialog').live('click', function()
{
$.ajaxSetup({ async: false });
var selected = [];
$("#[id*=LocalClocks]").each(function()
{
if(false != $(this).is(':checked'))
{
var string = $(this).attr('id').replace('LocalClocks', '');
string = string.substring(10);
selected.push(string);
}
});
if(0 === selected.length)
{
$selError.dialog('open');
$selError.text('No Local Clocks Were Selected')
}
else
{
$.post('/LocalClocks/editSelected', { "data[Session][selected]": selected }, function(data)
{
});
$editSel.load($(this).attr('href'), function ()
{
$editSel.dialog('open');
});
}
return false;
});
This was working when I was using jquery-1.4.2.min.js, but I am using jquery1.7 now.
I also ended up putting the first file with all the variables inside of $(document).ready(function(){}); I tried putting the second file inside of a document.ready() function but that made no difference.
Any help would be great.
Thanks

You are dealing with an issue in scope. In javascript:
function foo() {
var greet = "hi";
}
function bar() {
console.log(greet); // will throw error
}
However:
var greet;
function foo() {
greet = "hi";
}
function bar() {
console.log(greet); // will log "hi"
}
You must define your variable in a common parent of both functions that need to access it. Unfortunately, since you do not use any modeling convention or framework, that is the window object (why are global variables bad?).
So, you must define var $whateveryouneed before and outside of both $(document).readys.
Also, keep the declaration and definition seperate. Your definition instantiates a jQuery object, so you must encapsulate it inside a $(document).ready() (use $(function() {}) instead):
var $editSel;
$(function () {
$editSel = $("#editSel_dialog").dialog(
{
autoOpen: false,
height: 530,
width: 800,
resizable: true,
modal: true,
buttons:
{
"Cancel": function()
{
$(this).dialog("close");
}
}
});
});

I don't think you can guarantee the order in which handlers will be fired, which means that the document ready may be fired in different order than you expect. Is the variable you are trying to access in the second file a global variable? Try to think about your variables scope as I would have thought this is the issue.

You cannot guarantee that one file will be loaded before the other. And you cannot guarantee that document.ready in one file will fire before the other.
Therefore, I suggest you wrap your code in functions and call them in a single document.ready handler in the order you need.
For example:
function initVariables(){
window.$editSel = ... // your code from the first file here
}
function initHandlers(){
// your code from the second file here
}
And then:
$(document).ready(function() {
initVariables();
initHandlers();
});
You'll notice that I used the global window object to expose your variable. It would be even better if you used a common namespace for them.

jQuery: Call a function twice

I'm trying to run a function twice. Once when the page loads, and then again on click. Not sure what I'm doing wrong. Here is my code:
$('div').each(function truncate() {
$(this).addClass('closed').children().slice(0,2).show().find('.truncate').show();
});
$('.truncate').click(function() {
if ($(this).parent().hasClass('closed')) {
$(this).parent().removeClass('closed').addClass('open').children().show();
}
else if ($(this).parent().hasClass('open')) {
$(this).parent().removeClass('open').addClass('closed');
$('div').truncate();
$(this).show();
}
});
The problem is on line 13 where I call the truncate(); function a second time. Any idea why it's not working?
Edit jsFiddle here: http://jsfiddle.net/g6PLu/

That's a named function literal.
The name is only visible within the scope of the function.
Therefore, truncate doesn't exist outside of the handler.
Instead, create a normal function and pass it to each():
function truncate() { ...}
$('div').each(truncate);

What's the error message do you get?
You should create function and then call it as per requirement
Define the function
function truncate(){
$('div').each(function(){
});
}
Then call the function
truncate();

Another approach is to establish, then trigger, a custom event :
$('div').on('truncate', function() {
$(this).......;
}).trigger('truncate');
Then, wherever else you need the same action, trigger the event again.
To truncate all divs :
$('div').trigger('truncate');
Similarly you can truncate just one particular div :
$('div#myDiv').trigger('truncate');
The only prerequisite is that the custom event handler has been attached, so ...
$('p').trigger('truncate');
would do nothing because a truncate handler has not been established for p elements.

I know there's already an accepted answer, but I think the best solution would be a plugin http://jsfiddle.net/g6PLu/13/ It seems to be in the spirit of what the OP wants (to be able to call $('div').truncate). And makes for much cleaner code
(function($) {
$.fn.truncate = function() {
this.addClass('closed').children(":not('.truncate')").hide().slice(0,2).show();
};
$.fn.untruncate = function() {
this.removeClass('closed').children().show();
};
})(jQuery);
$('div').truncate();
$('.truncate').click(function() {
var $parent = $(this).parent();
if ($parent.hasClass('closed')) {
$parent.untruncate();
} else {
$parent.truncate();
}
});

FadeOut, Replace HTML & FadeIn

I'm having a few issues getting a simple JQuery function to work that fades an element out, replaces the image within and fades back in again.
My function looks like this:
function nextPage() {
$("#leftPage").fadeOut("slow", function() {
$("#leftPage").html="<img src='page4.jpg'>";
$("#leftPage").fadeIn("slow");
});
$("#rightPage").fadeOut("slow", function() {
$("#rightPage").html="<img src='page5.jpg'>";
$("#rightPage").fadeIn("slow");
});
}
The fade in/out section works fine but the HTML is not being replaced with the new images. Can you see a problem with this?

function nextPage() {
$("#leftPage").fadeOut("slow", function () {
$("#leftPage").html("<img src='page4.jpg'>");
$("#leftPage").fadeIn("slow");
});
$("#rightPage").fadeOut("slow", function () {
$("#rightPage").html("<img src='page5.jpg'>");
$("#rightPage").fadeIn("slow");
});
}
You're assigning a string to .html which is actually a function that takes a string as an argument, instead of being a property you can assign things to.
Notice I've changed .html = "" to .html("") in the above snippet. This now passes a string to .html(), which updates the element accordingly.

The correct syntax for .html() is:
$("#leftPage").html("<img src='page4.jpg'>");

Try this:
function nextPage() {
$("#leftPage").fadeOut("slow", function() {
$("#leftPage").html("<img src='page4.jpg'>");
$("#leftPage").fadeIn("slow");
});
$("#rightPage").fadeOut("slow", function() {
$("#rightPage").html("<img src='page5.jpg'>");
$("#rightPage").fadeIn("slow");
});
}
jquery's html is a function, not a property. You pass in the html you want to replace the elements contents with as a parameter

Try:
$("#leftPage").html("<img src='page4.jpg'>");
and:
$("#rightPage").html("<img src='page5.jpg'>");

You're using jQuery's .html() wrong
function nextPage() {
$("#leftPage").fadeOut("slow", function() {
$("#leftPage").html("<img src='page4.jpg'>");
$("#leftPage").fadeIn("slow");
});
$("#rightPage").fadeOut("slow", function() {
$("#rightPage").html("<img src='page5.jpg'>");
$("#rightPage").fadeIn("slow");
});
}

calling Jquery function from javascript

How can i call a jQuery function from javascript?
//jquery
$(function() {
function my_fun(){
/.. some operations ../
}
});
//just js
function js_fun () {
my_fun(); //== call jquery function
}

Yes you can (this is how I understand the original question).
Here is how I did it. Just tie it into outside context.
For example:
//javascript
my_function = null;
//jquery
$(function() {
function my_fun(){
/.. some operations ../
}
my_function = my_fun;
})
//just js
function js_fun () {
my_function(); //== call jquery function - just Reference is globally defined not function itself
}
I encountered this same problem when trying to access methods of the object, that was instantiated
on DOM object ready only. Works. My example:
MyControl.prototype = {
init: function {
// init something
}
update: function () {
// something useful, like updating the list items of control or etc.
}
}
MyCtrl = null;
// create jquery plug-in
$.fn.aControl = function () {
var control = new MyControl(this);
control.init();
MyCtrl = control; // here is the trick
return control;
}
now you can use something simple like:
function() = {
MyCtrl.update(); // yes!
}

You can't.
function(){
function my_fun(){
/.. some operations ../
}
}
That is a closure. my_fun() is defined only inside of that anonymous function. You can only call my_fun() if you declare it at the correct level of scope, i.e., globally.
$(function () {/* something */}) is an IIFE, meaning it executes immediately when the DOM is ready. By declaring my_fun() inside of that anonymous function, you prevent the rest of the script from "seeing" it.
Of course, if you want to run this function when the DOM has fully loaded, you should do the following:
function my_fun(){
/* some operations */
}
$(function(){
my_fun(); //run my_fun() ondomready
});
// just js
function js_fun(){
my_fun(); //== call my_fun() again
}

var jqueryFunction;
$().ready(function(){
//jQuery function
jqueryFunction = function( _msg )
{
alert( _msg );
}
})
//javascript function
function jsFunction()
{
//Invoke jQuery Function
jqueryFunction("Call from js to jQuery");
}
http://www.designscripting.com/2012/08/call-jquery-function-from-javascript/

<script>
// Instantiate your javascript function
niceJavascriptRoutine = null;
// Begin jQuery
$(document).ready(function() {
// Your jQuery function
function niceJqueryRoutine() {
// some code
}
// Point the javascript function to the jQuery function
niceJavaScriptRoutine = niceJueryRoutine;
});
</script>

jQuery functions are called just like JavaScript functions.
For example, to dynamically add the class "red" to the document element with the id "orderedlist" using the jQuery addClass function:
$("#orderedlist").addClass("red");
As opposed to a regular line of JavaScript calling a regular function:
var x = document.getElementById("orderedlist");
addClass() is a jQuery function, getElementById() is a JavaScript function.
The dollar sign function makes the jQuery addClass function available.
The only difference is the jQuery example is calling the addclass function of the jQuery object $("#orderedlist") and the regular example is calling a function of the document object.
In your code
$(function() {
// code to execute when the DOM is ready
});
Is used to specify code to run when the DOM is ready.
It does not differentiate (as you may think) what is "jQuery code" from regular JavaScript code.
So, to answer your question, just call functions you defined as you normally would.
//create a function
function my_fun(){
// call a jQuery function:
$("#orderedlist").addClass("red");
}
//call the function you defined:
myfun();

I made it...
I just write
jQuery('#container').append(html)
instead
document.getElementById('container').innerHTML += html;

//javascript function calling an jquery function
//In javascript part
function js_show_score()
{
//we use so many javascript library, So please use 'jQuery' avoid '$'
jQuery(function(){
//Call any jquery function
show_score(); //jquery function
});(jQuery);
}
//In Jquery part
jQuery(function(){
//Jq Score function
function show_score()
{
$('#score').val("10");
}
});(jQuery);

My problem was that I was looking at it from the long angle:
function new_line() {
var html= '<div><br><input type="text" value="" id="dateP_'+ i +'"></div>';
document.getElementById("container").innerHTML += html;
$('#dateP_'+i).datepicker({
showOn: 'button',
buttonImage: 'calendar.gif',
buttonImageOnly: true
});
i++;
}

<script>
$.myjQuery = function() {
alert("jQuery");
};
$(document).ready(function() {
alert("Welcome!");
});
function display() {
$.myjQuery();
};
</script>
<input type="button" value="submit" onclick=" display();">
Hope this will work for you!