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Safely / completely remove element from DOM [duplicate]

When removing an element with standard JavaScript, you must go to its parent first:
var element = document.getElementById("element-id");
element.parentNode.removeChild(element);
Having to go to the parent node first seems a bit odd to me, is there a reason JavaScript works like this?

I know that augmenting native DOM functions isn't always the best or most popular solution, but this works fine for modern browsers.
Element.prototype.remove = function() {
this.parentElement.removeChild(this);
}
NodeList.prototype.remove = HTMLCollection.prototype.remove = function() {
for(var i = this.length - 1; i >= 0; i--) {
if(this[i] && this[i].parentElement) {
this[i].parentElement.removeChild(this[i]);
}
}
}
And then you can remove elements like this
document.getElementById("my-element").remove();
or
document.getElementsByClassName("my-elements").remove();
Note: this solution doesn't work for IE 7 and below. For more info about extending the DOM read this article.
EDIT: Reviewing my answer in 2019, node.remove() has come to the rescue and can be used as follows (without the polyfill above):
document.getElementById("my-element").remove();
or
[...document.getElementsByClassName("my-elements")].map(n => n && n.remove());
These functions are available in all modern browsers (not IE). Read more on MDN.

Crossbrowser and IE >= 11:
document.getElementById("element-id").outerHTML = "";

You could make a remove function so that you wouldn't have to think about it every time:
function removeElement(id) {
var elem = document.getElementById(id);
return elem.parentNode.removeChild(elem);
}

Update 2011
This was added to the DOM spec back in 2011, so you can just use:
element.remove()
The DOM is organized in a tree of nodes, where each node has a value, along with a list of references to its child nodes. So element.parentNode.removeChild(element) mimics exactly what is happening internally: First you go the parent node, then remove the reference to the child node.
As of DOM4, a helper function is provided to do the same thing: element.remove(). This works in 96% of browsers (as of 2020), but not IE 11.
If you need to support older browsers, you can:
Remove elements via the parent node
Modify the native DOM functions, as in Johan Dettmar's answer, or
Use a DOM4 polyfill.

It's what the DOM supports. Search that page for "remove" or "delete" and removeChild is the only one that removes a node.

For removing one element:
var elem = document.getElementById("yourid");
elem.parentElement.removeChild(elem);
For removing all the elements with for example a certain class name:
var list = document.getElementsByClassName("yourclassname");
for(var i = list.length - 1; 0 <= i; i--)
if(list[i] && list[i].parentElement)
list[i].parentElement.removeChild(list[i]);

you can just use element.remove()

You can directly remove that element by using remove() method of DOM.
here's an example:
let subsWrapper = document.getElementById("element_id");
subsWrapper.remove();
//OR directly.
document.getElementById("element_id").remove();

The ChildNode.remove() method removes the object from the tree it belongs to.
https://developer.mozilla.org/en-US/docs/Web/API/ChildNode/remove
Here is a fiddle that shows how you can call document.getElementById('my-id').remove()
https://jsfiddle.net/52kp584L/
**
There is no need to extend NodeList. It has been implemented already.
**

According to DOM level 4 specs, which is the current version in development, there are some new handy mutation methods available: append(), prepend(), before(), after(), replace(), and remove().
https://catalin.red/removing-an-element-with-plain-javascript-remove-method/

You can simply use
document.getElementById("elementID").outerHTML="";
It works in all browsers, even on Internet Explorer.

Having to go to the parent node first seems a bit odd to me, is there a reason JavaScript works like this?
The function name is removeChild(), and how is it possible to remove the child when there's no parent? :)
On the other hand, you do not always have to call it as you have shown. element.parentNode is only a helper to get the parent node of the given node. If you already know the parent node, you can just use it like this:
Ex:
// Removing a specified element when knowing its parent node
var d = document.getElementById("top");
var d_nested = document.getElementById("nested");
var throwawayNode = d.removeChild(d_nested);
https://developer.mozilla.org/en-US/docs/Web/API/Node/removeChild
=========================================================
To add something more:
Some answers have pointed out that instead of using parentNode.removeChild(child);, you can use elem.remove();. But as I have noticed, there is a difference between the two functions, and it's not mentioned in those answers.
If you use removeChild(), it will return a reference to the removed node.
var removedChild = element.parentNode.removeChild(element);
console.log(removedChild); //will print the removed child.
But if you use elem.remove();, it won't return you the reference.
var el = document.getElementById('Example');
var removedChild = el.remove(); //undefined
https://developer.mozilla.org/en-US/docs/Web/API/ChildNode/remove
This behavior can be observed in Chrome and FF. I believe It's worth noticing :)
Hope my answer adds some value to the question and will be helpful!!

Functions that use ele.parentNode.removeChild(ele) won't work for elements you've created but not yet inserted into the HTML. Libraries like jQuery and Prototype wisely use a method like the following to evade that limitation.
_limbo = document.createElement('div');
function deleteElement(ele){
_limbo.appendChild(ele);
_limbo.removeChild(ele);
}
I think JavaScript works like that because the DOM's original designers held parent/child and previous/next navigation as a higher priority than the DHTML modifications that are so popular today. Being able to read from one <input type='text'> and write to another by relative location in the DOM was useful in the mid-90s, a time when the dynamic generation of entire HTML forms or interactive GUI elements was barely a twinkle in some developer's eye.

Shortest
I improve Sai Sunder answer because OP uses ID which allows to avoid getElementById:
elementId.remove();
box2.remove(); // remove BOX 2
this["box-3"].remove(); // remove BOX 3 (for Id with 'minus' character)
<div id="box1">My BOX 1</div>
<div id="box2">My BOX 2</div>
<div id="box-3">My BOX 3</div>
<div id="box4">My BOX 4</div>

Having to go to the parent node first seems a bit odd to me, is there
a reason JavaScript works like this?
IMHO: The reason for this is the same as I've seen in other environments: You are performing an action based on your "link" to something. You can't delete it while you're linked to it.
Like cutting a tree limb. Sit on the side closest to the tree while cutting or the result will be ... unfortunate (although funny).

From what I understand, removing a node directly does not work in Firefox, only Internet Explorer. So, to support Firefox, you have to go up to the parent to remove it's child.
Ref: http://chiragrdarji.wordpress.com/2007/03/16/removedelete-element-from-page-using-javascript-working-in-firefoxieopera/

This one actually comes from Firefox... for once, IE was ahead of the pack and allowed the removal of an element directly.
This is just my assumption, but I believe the reason that you must remove a child through the parent is due to an issue with the way Firefox handled the reference.
If you call an object to commit hari-kari directly, then immediately after it dies, you are still holding that reference to it. This has the potential to create several nasty bugs... such as failing to remove it, removing it but keeping references to it that appear valid, or simply a memory leak.
I believe that when they realized the issue, the workaround was to remove an element through its parent because when the element is gone, you are now simply holding a reference to the parent. This would stop all that unpleasantness, and (if closing down a tree node by node, for example) would 'zip-up' rather nicely.
It should be an easily fixable bug, but as with many other things in web programming, the release was probably rushed, leading to this... and by the time the next version came around, enough people were using it that changing this would lead to breaking a bunch of code.
Again, all of this is simply my guesswork.
I do, however, look forward to the day when web programming finally gets a full spring cleaning, all these strange little idiosyncracies get cleaned up, and everyone starts playing by the same rules.
Probably the day after my robot servant sues me for back wages.

// http://javascript.crockford.com/memory/leak.html
// cleans dom element to prevent memory leaks
function domPurge(d) {
var a = d.attributes, i, l, n;
if (a) {
for (i = a.length - 1; i >= 0; i -= 1) {
n = a[i].name;
if (typeof d[n] === 'function') {
d[n] = null;
}
}
}
a = d.childNodes;
if (a) {
l = a.length;
for (i = 0; i < l; i += 1) {
domPurge(d.childNodes[i]);
}
}
}
function domRemove(id) {
var elem = document.getElementById(id);
domPurge(elem);
return elem.parentNode.removeChild(elem);
}

This is the best function to remove an element without script error:
function Remove(EId)
{
return(EObj=document.getElementById(EId))?EObj.parentNode.removeChild(EObj):false;
}
Note to EObj=document.getElementById(EId).
This is ONE equal sign not ==.
if element EId exists then the function removes it, otherwise it returns false, not error.

Select tags that starts with "x-" in jQuery

How can I select nodes that begin with a "x-" tag name, here is an hierarchy DOM tree example:
<div>
<x-tab>
<div></div>
<div>
<x-map></x-map>
</div>
</x-tab>
</div>
<x-footer></x-footer>
jQuery does not allow me to query $('x-*'), is there any way that I could achieve this?

The below is just working fine. Though I am not sure about performance as I am using regex.
$('body *').filter(function(){
return /^x-/i.test(this.nodeName);
}).each(function(){
console.log(this.nodeName);
});
Working fiddle
PS: In above sample, I am considering body tag as parent element.
UPDATE :
After checking Mohamed Meligy's post, It seems regex is faster than string manipulation in this condition. and It could become more faster (or same) if we use find. Something like this:
$('body').find('*').filter(function(){
return /^x-/i.test(this.nodeName);
}).each(function(){
console.log(this.nodeName);
});
jsperf test
UPDATE 2:
If you want to search in document then you can do the below which is fastest:
$(Array.prototype.slice.call(document.all)).filter(function () {
return /^x-/i.test(this.nodeName);
}).each(function(){
console.log(this.nodeName);
});
jsperf test

There is no native way to do this, it has worst performance, so, just do it yourself.
Example:
var results = $("div").find("*").filter(function(){
return /^x\-/i.test(this.nodeName);
});
Full example:
http://jsfiddle.net/6b8YY/3/
Notes: (Updated, see comments)
If you are wondering why I use this way for checking tag name, see:
JavaScript: case-insensitive search
and see comments as well.
Also, if you are wondering about the find method instead of adding to selector, since selectors are matched from right not from left, it may be better to separate the selector. I could also do this:
$("*", $("div")). Preferably though instead of just div add an ID or something to it so that parent match is quick.
In the comments you'll find a proof that it's not faster. This applies to very simple documents though I believe, where the cost of creating a jQuery object is higher than the cost of searching all DOM elements. In realistic page sizes though this will not be the case.
Update:
I also really like Teifi's answer. You can do it in one place and then reuse it everywhere. For example, let me mix my way with his:
// In some shared libraries location:
$.extend($.expr[':'], {
x : function(e) {
return /^x\-/i.test(this.nodeName);
}
});
// Then you can use it like:
$(function(){
// One way
var results = $("div").find(":x");
// But even nicer, you can mix with other selectors
// Say you want to get <a> tags directly inside x-* tags inside <section>
var anchors = $("section :x > a");
// Another example to show the power, say using a class name with it:
var highlightedResults = $(":x.highlight");
// Note I made the CSS class right most to be matched first for speed
});
It's the same performance hit, but more convenient API.

It might not be efficient, but consider it as a last option if you do not get any answer.
Try adding a custom attribute to these tags. What i mean is when you add a tag for eg. <x-tag>, add a custom attribute with it and assign it the same value as the tag, so the html looks like <x-tag CustAttr="x-tag">.
Now to get tags starting with x-, you can use the following jQuery code:
$("[CustAttr^=x-]")
and you will get all the tags that start with x-

custom jquery selector
jQuery(function($) {
$.extend($.expr[':'], {
X : function(e) {
return /^x-/i.test(e.tagName);
}
});
});
than, use $(":X") or $("*:X") to select your nodes.

Although this does not answer the question directly it could provide a solution, by "defining" the tags in the selector you can get all of that type?
$('x-tab, x-map, x-footer')

Workaround: if you want this thing more than once, it might be a lot more efficient to add a class based on the tag - which you only do once at the beginning, and then you filter for the tag the trivial way.
What I mean is,
function addTagMarks() {
// call when the document is ready, or when you have new tags
var prefix = "tag--"; // choose a prefix that avoids collision
var newbies = $("*").not("[class^='"+prefix+"']"); // skip what's done already
newbies.each(function() {
var tagName = $(this).prop("tagName").toLowerCase();
$(this).addClass(prefix + tagName);
});
}
After this, you can do a $("[class^='tag--x-']") or the same thing with querySelectorAll and it will be reasonably fast.

See if this works!
function getXNodes() {
var regex = /x-/, i = 0, totalnodes = [];
while (i !== document.all.length) {
if (regex.test(document.all[i].nodeName)) {
totalnodes.push(document.all[i]);
}
i++;
}
return totalnodes;
}

Demo Fiddle
var i=0;
for(i=0; i< document.all.length; i++){
if(document.all[i].nodeName.toLowerCase().indexOf('x-') !== -1){
$(document.all[i].nodeName.toLowerCase()).addClass('test');
}
}

Try this
var test = $('[x-]');
if(test)
alert('eureka!');
Basically jQuery selector works like CSS selector.
Read jQuery selector API here.

c.replace is not a function

Hi everyone,
Actually, i got "c.replace is not a function" while i was trying to delete some DOM elements and..i don't understand.
i'd like to delete some tags from the DOM and so, i did it :
var liste=document.getElementById("tabs").getElementsByTagName("li");
for(i=0;i<liste.length;i++)
{
if(liste[i].id==2)
{
$("#tabs").detach(liste[i]);
}
}
I tried .detach and .remove but it's the same. My version of jQuery is 1.7.1.min.js.
Thanks for help.

order of iteration on a NodeLIst
Doing forward iteration of a NodeList that is being modified when you remove an element can be an issue. Iterate in reverse when removing elements from the DOM.
misuse of detach()
Also, the arguments to .detach() do not perform a nested find, but rather act as a filter on the existing element(s) in the jQuery object, and should be passed a string. It seems that you actually want to detach the li, which would mean that you'd need to call .detach() on the li itself...
var liste=document.getElementById("tabs").getElementsByTagName("li");
var i = liste.length
while(i--) {
if(liste[i].id==2) {
$(liste[i]).detach();
}
}
remove() may be preferred
Keep in mind that if you use .detach(), any jQuery data is retained. If you have no further use for the element, you should be using .remove() instead.
// ...
$(liste[i]).remove(); // clean up all data
code reduction
Finally, since you're using jQuery, you could just do all this in the selector...
$('#tabs li[id=2]').remove(); // or .detach() if needed
valid id attributes
Keep these items in mind with respect to IDs...
It's invalid to have duplicate IDs on a page
It's invalid in HTML4 to have an ID that starts with a number
In the selector above, I used the attribute-equals filter, so it'll work, but you should really be using valid HTML to avoid problems elsewhere.

liste is not (yet) a jQuery object. use $(liste[i])
or use
var liste= $('#tabs li');

Maybe I'm missing something, but is the id suppose to match the number 2.
var liste=document.getElementById("tabs").getElementsByTagName("li");
for(i=0;i<liste.length;i++) {
if(liste[i].id==2) {
$(liste[i]).detach();
}
}
Since you are already using jQuery, why not just do:
$("li", "#tabs").filter("#2").detach();

var two = document.getElementById('2');
two.parentNode.removeChild(two);

JavaScript/JQuery: use $(this) in a variable-name

I'm writing a jquery-plugin, that changes a css-value of certain elements on certain user-actions.
On other actions the css-value should be reseted to their initial value.
As I found no way to get the initial css-values back, I just created an array that stores all initial values in the beginning.
I did this with:
var initialCSSValue = new Array()
quite in the beginning of my plugin and later, in some kind of setup-loop where all my elements get accessed I used
initialCSSValue[$(this)] = parseInt($(this).css('<CSS-attribute>'));
This works very fine in Firefox.
However, I just found out, that IE (even v8) has problems with accessing the certain value again using
initialCSSValue[$(this)]
somewhere else in the code. I think this is due to the fact, that I use an object ($(this)) as a variable-name.
Is there a way arround this problem?
Thank you

Use $(this).data()
At first I was going to suggest using a combination of the ID and the attribute name, but every object might not have an ID. Instead, use the jQuery Data functions to attach the information directly to the element for easy, unique, access.
Do something like this (Where <CSS-attribute> is replaced with the css attribute name):
$(this).data('initial-<CSS-attribute>', parseInt( $(this).css('<CSS-attribute>') ) );
Then you can access it again like this:
$(this).data('initial-<CSS-attribute>');
Alternate way using data:
In your plugin, you could make a little helper function like this, if you wanted to avoid too much data usage:
var saveCSS = function (el, css_attribute ) {
var data = $(el).data('initial-css');
if(!data) data = {};
data[css_attribute] = $(el).css(css_attribute);
$(el).data('initial-css', data);
}
var readCSS = function (el, css_attribute) {
var data = $(el).data('initial-css');
if(data && data[css_attribute])
return data[css_attribute];
else
return "";
}

Indexing an array with a jQuery object seems fishy. I'd use the ID of the object to key the array.
initialCSSValue[$(this).attr("id")] = parseInt...

Oh please, don't do that... :)
Write some CSS and use the addClass and removeClass - it leaves the styles untouched afterwards.

if anybody wants to see the plugin in action, see it here:
http://www.sj-wien.at/leopoldstadt/zeug/marcel/slidlabel/jsproblem.html

jQuery Tips and Tricks

Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions.
Syntax
Shorthand for the ready-event by roosteronacid
Line breaks and chainability by roosteronacid
Nesting filters by Nathan Long
Cache a collection and execute commands on the same line by roosteronacid
Contains selector by roosteronacid
Defining properties at element creation by roosteronacid
Access jQuery functions as you would an array by roosteronacid
The noConflict function - Freeing up the $ variable by Oli
Isolate the $ variable in noConflict mode by nickf
No-conflict mode by roosteronacid
Data Storage
The data function - bind data to elements by TenebrousX
HTML5 data attributes support, on steroids! by roosteronacid
The jQuery metadata plug-in by Filip Dupanović
Optimization
Optimize performance of complex selectors by roosteronacid
The context parameter by lupefiasco
Save and reuse searches by Nathan Long
Creating an HTML Element and keeping a reference, Checking if an element exists, Writing your own selectors by Andreas Grech
Miscellaneous
Check the index of an element in a collection by redsquare
Live event handlers by TM
Replace anonymous functions with named functions by ken
Microsoft AJAX framework and jQuery bridge by Slace
jQuery tutorials by egyamado
Remove elements from a collection and preserve chainability by roosteronacid
Declare $this at the beginning of anonymous functions by Ben
FireBug lite, Hotbox plug-in, tell when an image has been loaded and Google CDN by Colour Blend
Judicious use of third-party jQuery scripts by harriyott
The each function by Jan Zich
Form Extensions plug-in by Chris S
Asynchronous each function by OneNerd
The jQuery template plug-in: implementing complex logic using render-functions by roosteronacid

Creating an HTML Element and keeping a reference
var newDiv = $("<div />");
newDiv.attr("id", "myNewDiv").appendTo("body");
/* Now whenever I want to append the new div I created,
I can just reference it from the "newDiv" variable */
Checking if an element exists
if ($("#someDiv").length)
{
// It exists...
}
Writing your own selectors
$.extend($.expr[":"], {
over100pixels: function (e)
{
return $(e).height() > 100;
}
});
$(".box:over100pixels").click(function ()
{
alert("The element you clicked is over 100 pixels height");
});

jQuery's data() method is useful and not well known. It allows you to bind data to DOM elements without modifying the DOM.

Nesting Filters
You can nest filters (as nickf showed here).
.filter(":not(:has(.selected))")

I'm really not a fan of the $(document).ready(fn) shortcut. Sure it cuts down on the code but it also cuts way down on the readability of the code. When you see $(document).ready(...), you know what you're looking at. $(...) is used in far too many other ways to immediately make sense.
If you have multiple frameworks you can use jQuery.noConflict(); as you say, but you can also assign a different variable for it like this:
var $j = jQuery.noConflict();
$j("#myDiv").hide();
Very useful if you have several frameworks that can be boiled down to $x(...)-style calls.

Ooooh, let's not forget jQuery metadata! The data() function is great, but it has to be populated via jQuery calls.
Instead of breaking W3C compliance with custom element attributes such as:
<input
name="email"
validation="required"
validate="email"
minLength="7"
maxLength="30"/>
Use metadata instead:
<input
name="email"
class="validation {validate: email, minLength: 2, maxLength: 50}" />
<script>
jQuery('*[class=validation]').each(function () {
var metadata = $(this).metadata();
// etc.
});
</script>

Live Event Handlers
Set an event handler for any element that matches a selector, even if it gets added to the DOM after the initial page load:
$('button.someClass').live('click', someFunction);
This allows you to load content via ajax, or add them via javascript and have the event handlers get set up properly for those elements automatically.
Likewise, to stop the live event handling:
$('button.someClass').die('click', someFunction);
These live event handlers have a few limitations compared to regular events, but they work great for the majority of cases.
For more info see the jQuery Documentation.
UPDATE: live() and die() are deprecated in jQuery 1.7. See http://api.jquery.com/on/ and http://api.jquery.com/off/ for similar replacement functionality.
UPDATE2: live() has been long deprecated, even before jQuery 1.7. For versions jQuery 1.4.2+ before 1.7 use delegate() and undelegate(). The live() example ($('button.someClass').live('click', someFunction);) can be rewritten using delegate() like that: $(document).delegate('button.someClass', 'click', someFunction);.

Replace anonymous functions with named functions. This really supercedes the jQuery context, but it comes into play more it seems like when using jQuery, due to its reliance on callback functions. The problems I have with inline anonymous functions, are that they are harder to debug (much easier to look at a callstack with distinctly-named functions, instead 6 levels of "anonymous"), and also the fact that multiple anonymous functions within the same jQuery-chain can become unwieldy to read and/or maintain. Additionally, anonymous functions are typically not re-used; on the other hand, declaring named functions encourages me to write code that is more likely to be re-used.
An illustration; instead of:
$('div').toggle(
function(){
// do something
},
function(){
// do something else
}
);
I prefer:
function onState(){
// do something
}
function offState(){
// do something else
}
$('div').toggle( offState, onState );

Defining properties at element creation
In jQuery 1.4 you can use an object literal to define properties when you create an element:
var e = $("<a />", { href: "#", class: "a-class another-class", title: "..." });
... You can even add styles:
$("<a />", {
...
css: {
color: "#FF0000",
display: "block"
}
});
Here's a link to the documentation.

instead of using a different alias for the jQuery object (when using noConflict), I always write my jQuery code by wrapping it all in a closure. This can be done in the document.ready function:
var $ = someOtherFunction(); // from a different library
jQuery(function($) {
if ($ instanceOf jQuery) {
alert("$ is the jQuery object!");
}
});
alternatively you can do it like this:
(function($) {
$('...').etc() // whatever jQuery code you want
})(jQuery);
I find this to be the most portable. I've been working on a site which uses both Prototype AND jQuery simultaneously and these techniques have avoided all conflicts.

Check the Index
jQuery has .index but it is a pain to use, as you need the list of elements, and pass in the element you want the index of:
var index = e.g $('#ul>li').index( liDomObject );
The following is much easier:
If you want to know the index of an element within a set (e.g. list items) within a unordered list:
$("ul > li").click(function () {
var index = $(this).prevAll().length;
});

Shorthand for the ready-event
The explicit and verbose way:
$(document).ready(function ()
{
// ...
});
The shorthand:
$(function ()
{
// ...
});

On the core jQuery function, specify the context parameter in addition to the selector parameter. Specifying the context parameter allows jQuery to start from a deeper branch in the DOM, rather than from the DOM root. Given a large enough DOM, specifying the context parameter should translate to performance gains.
Example: Finds all inputs of type radio within the first form in the document.
$("input:radio", document.forms[0]);
Reference: http://docs.jquery.com/Core/jQuery#expressioncontext

Not really jQuery only but I made a nice little bridge for jQuery and MS AJAX:
Sys.UI.Control.prototype.j = function Sys$UI$Control$j(){
return $('#' + this.get_id());
}
It's really nice if you're doing lots of ASP.NET AJAX, since jQuery is supported by MS now having a nice bridge means it's really easy to do jQuery operations:
$get('#myControl').j().hide();
So the above example isn't great, but if you're writing ASP.NET AJAX server controls, makes it easy to have jQuery inside your client-side control implementation.

Optimize performance of complex selectors
Query a subset of the DOM when using complex selectors drastically improves performance:
var subset = $("");
$("input[value^='']", subset);

Speaking of Tips and Tricks and as well some tutorials. I found these series of tutorials (“jQuery for Absolute Beginners” Video Series) by Jeffery Way are VERY HELPFUL.
It targets those developers who are new to jQuery. He shows how to create many cool stuff with jQuery, like animation, Creating and Removing Elements and more...
I learned a lot from it. He shows how it's easy to use jQuery.
Now I love it and i can read and understand any jQuery script even if it's complex.
Here is one example I like "Resizing Text"
1- jQuery...
<script language="javascript" type="text/javascript">
$(function() {
$('a').click(function() {
var originalSize = $('p').css('font-size'); // get the font size
var number = parseFloat(originalSize, 10); // that method will chop off any integer from the specified variable "originalSize"
var unitOfMeasure = originalSize.slice(-2);// store the unit of measure, Pixle or Inch
$('p').css('font-size', number / 1.2 + unitOfMeasure);
if(this.id == 'larger'){$('p').css('font-size', number * 1.2 + unitOfMeasure);}// figure out which element is triggered
});
});
</script>
2- CSS Styling...
<style type="text/css" >
body{ margin-left:300px;text-align:center; width:700px; background-color:#666666;}
.box {width:500px; text-align:justify; padding:5px; font-family:verdana; font-size:11px; color:#0033FF; background-color:#FFFFCC;}
</style>
2- HTML...
<div class="box">
Larger |
Smaller
<p>
In today’s video tutorial, I’ll show you how to resize text every time an associated anchor tag is clicked. We’ll be examining the “slice”, “parseFloat”, and “CSS” Javascript/jQuery methods.
</p>
</div>
Highly recommend these tutorials...
http://blog.themeforest.net/screencasts/jquery-for-absolute-beginners-video-series/

Asynchronous each() function
If you have really complex documents where running the jquery each() function locks up the browser during the iteration, and/or Internet Explorer pops up the 'do you want to continue running this script' message, this solution will save the day.
jQuery.forEach = function (in_array, in_pause_ms, in_callback)
{
if (!in_array.length) return; // make sure array was sent
var i = 0; // starting index
bgEach(); // call the function
function bgEach()
{
if (in_callback.call(in_array[i], i, in_array[i]) !== false)
{
i++; // move to next item
if (i < in_array.length) setTimeout(bgEach, in_pause_ms);
}
}
return in_array; // returns array
};
jQuery.fn.forEach = function (in_callback, in_optional_pause_ms)
{
if (!in_optional_pause_ms) in_optional_pause_ms = 10; // default
return jQuery.forEach(this, in_optional_pause_ms, in_callback); // run it
};
The first way you can use it is just like each():
$('your_selector').forEach( function() {} );
An optional 2nd parameter lets you specify the speed/delay in between iterations which may be useful for animations (the following example will wait 1 second in between iterations):
$('your_selector').forEach( function() {}, 1000 );
Remember that since this works asynchronously, you can't rely on the iterations to be complete before the next line of code, for example:
$('your_selector').forEach( function() {}, 500 );
// next lines of code will run before above code is complete
I wrote this for an internal project, and while I am sure it can be improved, it worked for what we needed, so hope some of you find it useful. Thanks -

Syntactic shorthand-sugar-thing--Cache an object collection and execute commands on one line:
Instead of:
var jQueryCollection = $("");
jQueryCollection.command().command();
I do:
var jQueryCollection = $("").command().command();
A somewhat "real" use case could be something along these lines:
var cache = $("#container div.usehovereffect").mouseover(function ()
{
cache.removeClass("hover").filter(this).addClass("hover");
});

I like declare a $this variable at the beginning of anonymous functions, so I know I can reference a jQueried this.
Like so:
$('a').each(function() {
var $this = $(this);
// Other code
});

Save jQuery Objects in Variables for Reuse
Saving a jQuery object to a variable lets you reuse it without having to search back through the DOM to find it.
(As #Louis suggested, I now use $ to indicate that a variable holds a jQuery object.)
// Bad: searching the DOM multiple times for the same elements
$('div.foo').each...
$('div.foo').each...
// Better: saving that search for re-use
var $foos = $('div.foo');
$foos.each...
$foos.each...
As a more complex example, say you've got a list of foods in a store, and you want to show only the ones that match a user's criteria. You have a form with checkboxes, each one containing a criteria. The checkboxes have names like organic and lowfat, and the products have corresponding classes - .organic, etc.
var $allFoods, $matchingFoods;
$allFoods = $('div.food');
Now you can keep working with that jQuery object. Every time a checkbox is clicked (to check or uncheck), start from the master list of foods and filter down based on the checked boxes:
// Whenever a checkbox in the form is clicked (to check or uncheck)...
$someForm.find('input:checkbox').click(function(){
// Start out assuming all foods should be showing
// (in case a checkbox was just unchecked)
var $matchingFoods = $allFoods;
// Go through all the checked boxes and keep only the foods with
// a matching class
this.closest('form').find("input:checked").each(function() {
$matchingFoods = $matchingFoods.filter("." + $(this).attr("name"));
});
// Hide any foods that don't match the criteria
$allFoods.not($matchingFoods).hide();
});

It seems that most of the interesting and important tips have been already mentioned, so this one is just a little addition.
The little tip is the jQuery.each(object, callback) function. Everybody is probably using the jQuery.each(callback) function to iterate over the jQuery object itself because it is natural. The jQuery.each(object, callback) utility function iterates over objects and arrays. For a long time, I somehow did not see what it could be for apart from a different syntax (I don’t mind writing all fashioned loops), and I’m a bit ashamed that I realized its main strength only recently.
The thing is that since the body of the loop in jQuery.each(object, callback) is a function, you get a new scope every time in the loop which is especially convenient when you create closures in the loop.
In other words, a typical common mistake is to do something like:
var functions = [];
var someArray = [1, 2, 3];
for (var i = 0; i < someArray.length; i++) {
functions.push(function() { alert(someArray[i]) });
}
Now, when you invoke the functions in the functions array, you will get three times alert with the content undefined which is most likely not what you wanted. The problem is that there is just one variable i, and all three closures refer to it. When the loop finishes, the final value of i is 3, and someArrary[3] is undefined. You could work around it by calling another function which would create the closure for you. Or you use the jQuery utility which it will basically do it for you:
var functions = [];
var someArray = [1, 2, 3];
$.each(someArray, function(item) {
functions.push(function() { alert(item) });
});
Now, when you invoke the functions you get three alerts with the content 1, 2 and 3 as expected.
In general, it is nothing you could not do yourself, but it’s nice to have.

Access jQuery functions as you would an array
Add/remove a class based on a boolean...
function changeState(b)
{
$("selector")[b ? "addClass" : "removeClass"]("name of the class");
}
Is the shorter version of...
function changeState(b)
{
if (b)
{
$("selector").addClass("name of the class");
}
else
{
$("selector").removeClass("name of the class");
}
}
Not that many use-cases for this. Never the less; I think it's neat :)
Update
Just in case you are not the comment-reading-type, ThiefMaster points out that the toggleClass accepts a boolean value, which determines if a class should be added or removed. So as far as my example code above goes, this would be the best approach...
$('selector').toggleClass('name_of_the_class', true/false);

Update:
Just include this script on the site and you’ll get a Firebug console that pops up for debugging in any browser. Not quite as full featured but it’s still pretty helpful! Remember to remove it when you are done.
<script type='text/javascript' src='http://getfirebug.com/releases/lite/1.2/firebug-lite-compressed.js'></script>
Check out this link:
From CSS Tricks
Update:
I found something new; its the the JQuery Hotbox.
JQuery Hotbox
Google hosts several JavaScript libraries on Google Code. Loading it from there saves bandwidth and it loads quick cos it has already been cached.
<script src="http://www.google.com/jsapi"></script>
<script type="text/javascript">
// Load jQuery
google.load("jquery", "1.2.6");
google.setOnLoadCallback(function() {
// Your code goes here.
});
</script>
Or
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.min.js" type="text/javascript"></script>
You can also use this to tell when an image is fully loaded.
$('#myImage').attr('src', 'image.jpg').load(function() {
alert('Image Loaded');
});
The "console.info" of firebug, which you can use to dump messages and variables to the screen without having to use alert boxes. "console.time" allows you to easily set up a timer to wrap a bunch of code and see how long it takes.
console.time('create list');
for (i = 0; i < 1000; i++) {
var myList = $('.myList');
myList.append('This is list item ' + i);
}
console.timeEnd('create list');

Use filtering methods over pseudo selectors when possible so jQuery can use querySelectorAll (which is much faster than sizzle). Consider this selector:
$('.class:first')
The same selection can be made using:
$('.class').eq(0)
Which is must faster because the initial selection of '.class' is QSA compatible

Remove elements from a collection and preserve chainability
Consider the following:
<ul>
<li>One</li>
<li>Two</li>
<li>Three</li>
<li>Four</li>
<li>Five</li>
</ul>
$("li").filter(function()
{
var text = $(this).text();
// return true: keep current element in the collection
if (text === "One" || text === "Two") return true;
// return false: remove current element from the collection
return false;
}).each(function ()
{
// this will alert: "One" and "Two"
alert($(this).text());
});
The filter() function removes elements from the jQuery object. In this case: All li-elements not containing the text "One" or "Two" will be removed.

Changing the type of an input element
I ran into this issue when I was trying to change the type of an input element already attached to the DOM. You have to clone the existing element, insert it before the old element, and then delete the old element. Otherwise it doesn't work:
var oldButton = jQuery("#Submit");
var newButton = oldButton.clone();
newButton.attr("type", "button");
newButton.attr("id", "newSubmit");
newButton.insertBefore(oldButton);
oldButton.remove();
newButton.attr("id", "Submit");

Judicious use of third-party jQuery scripts, such as form field validation or url parsing. It's worth seeing what's about so you'll know when you next encounter a JavaScript requirement.

Line-breaks and chainability
When chaining multiple calls on collections...
$("a").hide().addClass().fadeIn().hide();
You can increase readability with linebreaks. Like this:
$("a")
.hide()
.addClass()
.fadeIn()
.hide();

Use .stop(true,true) when triggering an animation prevents it from repeating the animation. This is especially helpful for rollover animations.
$("#someElement").hover(function(){
$("div.desc", this).stop(true,true).fadeIn();
},function(){
$("div.desc", this).fadeOut();
});

Using self-executing anonymous functions in a method call such as .append() to iterate through something. I.E.:
$("<ul>").append((function ()
{
var data = ["0", "1", "2", "3", "4", "5", "6"],
output = $("<div>"),
x = -1,
y = data.length;
while (++x < y) output.append("<li>" + info[x] + "</li>");
return output.children();
}()));
I use this to iterate through things that would be large and uncomfortable to break out of my chaining to build.

HTML5 data attributes support, on steroids!
The data function has been mentioned before. With it, you are able to associate data with DOM elements.
Recently the jQuery team has added support for HTML5 custom data-* attributes. And as if that wasn't enough; they've force-fed the data function with steroids, which means that you are able to store complex objects in the form of JSON, directly in your markup.
The HTML:
<p data-xyz = '{"str": "hi there", "int": 2, "obj": { "arr": [1, 2, 3] } }' />
The JavaScript:
var data = $("p").data("xyz");
data.str // "hi there"
typeof data.str // "string"
data.int + 2 // 4
typeof data.int // "number"
data.obj.arr.join(" + ") + " = 6" // "1 + 2 + 3 = 6"
typeof data.obj.arr // "object" ... Gobbles! Errrghh!