This jQuery Tutorial from http://www.w3schools.com

jQuery is a JavaScript Library.

jQuery greatly simplifies JavaScript programming.

jQuery is easy to learn.

The jQuery library can be added to a web page with a single line of markup.

What is jQuery?

jQuery is a library of JavaScript Functions.

jQuery is a lightweight "write less, do more" JavaScript library.

The jQuery library contains the following features:

HTML element selections
HTML element manipulation
CSS manipulation
HTML event functions
JavaScript Effects and animations
HTML DOM traversal and modification
AJAX
Utilities

Adding the jQuery Library to Your Pages

The jQuery library is stored as a single JavaScript file, containing all the jQuery methods.

It can be added to a web page with the following mark-up:

Please note that the <script> tag should be inside the page's <head> section.

Basic jQuery Example

The following example demonstrates the jQuery hide() method, hiding all <p> elements in an HTML document.

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

$(document).ready(function(){

$("button").click(function(){

$("p").hide();

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

Downloading jQuery

Two versions of jQuery are available for downloading: one minified and one uncompressed (for debugging or reading).

Both versions can be downloaded from jQuery.com.

Alternatives to Downloading

If you don't want to store the jQuery library on your own computer, you can use the hosted jQuery library from Google or Microsoft.

Google:

<html>

<head>

<script type="text/javascript"

src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js">

</script>

<script type="text/javascript">

$(document).ready(function(){

$("button").click(function(){

$("p").hide();

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

Microsoft

With jQuery you select (query) HTML elements and perform "actions" on them.

jQuery Syntax Examples

$(this).hide()
Demonstrates the jQuery hide() method, hiding the current HTML element.

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

$(document).ready(function(){

$("button").click(function(){

$(this).hide();

});

</script>

</head>

<body>

<button>Click me</button>

</body>

</html>

$("#test").hide()
Demonstrates the jQuery hide() method, hiding the element with id="test".

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

$(document).ready(function(){

$("button").click(function(){

$("#test").hide();

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p id="test">This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

$("p").hide()
Demonstrates the jQuery hide() method, hiding all <p> elements.
<html>
<head>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("button").click(function(){
$("p").hide();
});
});
</script>
</head>

<body>
<h2>This is a heading</h2>
<p>This is a paragraph.</p>
<p>This is another paragraph.</p>
<button>Click me</button>
</body>
</html>

$(".test").hide()
Demonstrates the jQuery hide() method, hiding all elements with class="test".

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

$(document).ready(function(){

$("button").click(function(){

$(".test").hide();

});

</script>

</head>

<body>

<h2 class="test">This is a heading</h2>

<p class="test">This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

jQuery Syntax

The jQuery syntax is tailor made for selecting HTML elements and perform some action on the element(s).

Basic syntax is: $(selector).action()

A dollar sign to define jQuery
A (selector) to "query (or find)" HTML elements
A jQuery action() to be performed on the element(s)

Examples:

$(this).hide() - hides current element

$("p").hide() - hides all paragraphs

$("p.test").hide() - hides all paragraphs with class="test"

$("#test").hide() - hides the element with id="test"

The Document Ready Function

You might have noticed that all jQuery methods, in our examples, are inside a document.ready() function:

$(document).ready(function(){

// jQuery functions go here...

});

This is to prevent any jQuery code from running before the document is finished loading (is ready).

Here are some examples of actions that can fail if functions are run before the document is fully loaded:

Trying to hide an element that doesn't exist
Trying to get the size of an image that is not loaded

jQuery selectors allow you to select and manipulate HTML elements as a group or as a single element.

jQuery Selectors

In the previous chapter we looked at some examples of how to select different HTML elements.

It is a key point to learn how jQuery selects exactly the elements you want to apply an effect to.

jQuery selectors allow you to select HTML elements (or groups of elements) by element name, attribute name or by content.

jQuery Element Selectors

jQuery uses CSS selectors to select HTML elements.

$("p") selects all <p> elements.

$("p.intro") selects all <p> elements with class="intro".

$("p#demo") selects all <p> elements with id="demo".

jQuery Attribute Selectors

jQuery uses XPath expressions to select elements with given attributes.

$("[href]") select all elements with an href attribute.

$("[href='#']") select all elements with an href value equal to "#".

$("[href!='#']") select all elements with an href attribute NOT equal to "#".

$("[href$='.jpg']") select all elements with an href attribute that ends with ".jpg".

jQuery CSS Selectors

jQuery CSS selectors can be used to change CSS properties for HTML elements.

The following example changes the background-color of all p elements to yellow:

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

$(document).ready(function(){

$("button").click(function(){

$("p").css("background-color","yellow");

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

Some More Examples

Syntax	Description
$(this)	Current HTML element
$("p")	All <p> elements
$("p.intro")	All <p> elements with class="intro"
$("p#intro")	All <p> elements with id="intro"
$("p#intro:first")	The first <p> element with id="intro"
$(".intro")	All elements with class="intro"
$("#intro")	The first element with id="intro"
$("ul li:first")	The first <li> element of each <ul>
$("[href$='.jpg']")	All elements with an href attribute that ends with ".jpg"
$("div#intro .head")	All elements with class="head" inside a <div> element with id="intro"

Selector	Example	Selects
*	$("*")	All elements
#id	$("#lastname")	The element with id=lastname
.class	$(".intro")	All elements with class="intro"
element	$("p")	All p elements
.class.class	$(".intro.demo")	All elements with the classes "intro" and "demo"

:first	$("p:first")	The first p element
:last	$("p:last")	The last p element
:even	$("tr:even")	All even tr elements
:odd	$("tr:odd")	All odd tr elements

:eq(index)	$("ul li:eq(3)")	The fourth element in a list (index starts at 0)
:gt(no)	$("ul li:gt(3)")	List elements with an index greater than 3
:lt(no)	$("ul li:lt(3)")	List elements with an index less than 3
:not(selector)	$("input:not(:empty)")	All input elements that are not empty

:header	$(":header")	All header elements h1, h2 ...
:animated	$(":animated")	All animated elements

:contains(text)	$(":contains('W3Schools')")	All elements which contains the text
:empty	$(":empty")	All elements with no child (elements) nodes
:hidden	$("p:hidden")	All hidden p elements
:visible	$("table:visible")	All visible tables

s1,s2,s3	$("th,td,.intro")	All elements with matching selectors

[attribute]	$("[href]")	All elements with a href attribute
[attribute=value]	$("[href='default.htm']")	All elements with a href attribute value equal to "default.htm"
[attribute!=value]	$("[href!='default.htm']")	All elements with a href attribute value not equal to "default.htm"
[attribute$=value]	$("[href$='.jpg']")	All elements with a href attribute value ending with ".jpg"

:input	$(":input")	All input elements
:text	$(":text")	All input elements with type="text"
:password	$(":password")	All input elements with type="password"
:radio	$(":radio")	All input elements with type="radio"
:checkbox	$(":checkbox")	All input elements with type="checkbox"
:submit	$(":submit")	All input elements with type="submit"
:reset	$(":reset")	All input elements with type="reset"
:button	$(":button")	All input elements with type="button"
:image	$(":image")	All input elements with type="image"
:file	$(":file")	All input elements with type="file"

:enabled	$(":enabled")	All enabled input elements
:disabled	$(":disabled")	All disabled input elements
:selected	$(":selected")	All selected input elements
:checked	$(":checked")	All checked input elements

jQuery is tailor made to handle events.

jQuery Event Functions

The jQuery event handling methods are core functions in jQuery.

Event handlers are method that are called when "something happens" in HTML. The term "triggered (or "fired") by an event" is often used.

It is common to put jQuery code into event handler methods in the <head> section:

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

$(document).ready(function(){

$("button").click(function(){

$("p").hide();

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

In the example above, a function is called when the click event for the button is triggered:

$("button").click(function() {..some code... } )

The method hides all <p> elements:

$("p").hide();

Functions In a Separate File

If your website contains a lot of pages, and you want your jQuery functions to be easy to maintain, put your jQuery functions in a separate .js file.

When we demonstrate jQuery here, the functions are added directly into the <head> section, However, sometimes it is preferable to place them in a separate file, like this (refer to the file with the src attribute):

Example

jQuery Name Conflicts

jQuery uses the $ sign as a shortcut for jQuery.

Some other JavaScript libraries also use the dollar sign for their functions.

The jQuery noConflict() method specifies a custom name (like jq), instead of using the dollar sign.

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

var jq=jQuery.noConflict();

jq(document).ready(function(){

jq("button").click(function(){

jq("p").hide();

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

jQuery Events

Here are some examples of event methods in jQuery:

Event Method	Description
$(document).ready(function)	Binds a function to the ready event of a document (when the document is finished loading)
$(selector).click(function)	Triggers, or binds a function to the click event of selected elements
$(selector).dblclick(function)	Triggers, or binds a function to the double click event of selected elements
$(selector).focus(function)	Triggers, or binds a function to the focus event of selected elements
$(selector).mouseover(function)	Triggers, or binds a function to the mouseover event of selected elements

jQuery Event Methods

Event methods trigger, or bind a function to an event for all matching elements.

Trigger example:

$("button").click() - triggers the click event for a button element.

Binding example:

$("button").click(function(){$("img").hide()}) - binds a function to the click event.

The following table lists all the methods used to handle events.

Method	Description
bind()	Add one or more event handlers to matching elements
blur()	Triggers, or binds a function to the blur event of selected elements
change()	Triggers, or binds a function to the change event of selected elements
click()	Triggers, or binds a function to the click event of selected elements
dblclick()	Triggers, or binds a function to the dblclick event of selected elements
delegate()	Add one or more event handlers to current, or future, specified child elements of the matching elements
die()	Remove all event handlers added with the live() function
error()	Triggers, or binds a function to the error event of selected elements
event.currentTarget	The current DOM element within the event bubbling phase
event.data	Contains the optional data passed to jQuery.fn.bind when the current executing handler was bound
event.isDefaultPrevented()	Returns whether event.preventDefault() was called for the event object
event.isImmediatePropagationStopped()	Returns whether event.stopImmediatePropagation() was called for the event object
event.isPropagationStopped()	Returns whether event.stopPropagation() was called for the event object
event.pageX	The mouse position relative to the left edge of the document
event.pageY	The mouse position relative to the top edge of the document
event.preventDefault()	Prevents the default action of the event
event.relatedTarget	The other DOM element involved in the event, if any
event.result	This attribute contains the last value returned by an event handler that was triggered by this event, unless the value was undefined
event.stopImmediatePropagation()	Prevents other event handlers from being called
event.stopPropagation()	Prevents the event from bubbling up the DOM tree, preventing any parent handlers from being notified of the event
event.target	The DOM element that initiated the event
event.timeStamp	This attribute returns the number of milliseconds since January 1, 1970, when the event is triggered
event.type	Describes the nature of the event
event.which	Which key or button was pressed for a key or button event
focus()	Triggers, or binds a function to the focus event of selected elements
focusin()	Binds a function to the focusin event of selected elements
focusout()	Binds a function to the focusout event of selected elements
hover()	Binds one or two functions to the hover event of selected elements
keydown()	Triggers, or binds a function to the keydown event of selected elements
keypress()	Triggers, or binds a function to the keypress event of selected elements
keyup()	Triggers, or binds a function to the keyup event of selected elements
live()	Add one or more event handlers to current, or future, matching elements
load()	Triggers, or binds a function to the load event of selected elements
mousedown()	Triggers, or binds a function to the mouse down event of selected elements
mouseenter()	Triggers, or binds a function to the mouse enter event of selected elements
mouseleave()	Triggers, or binds a function to the mouse leave event of selected elements
mousemove()	Triggers, or binds a function to the mouse move event of selected elements
mouseout()	Triggers, or binds a function to the mouse out event of selected elements
mouseover()	Triggers, or binds a function to the mouse over event of selected elements
mouseup()	Triggers, or binds a function to the mouse up event of selected elements
one()	Add one or more event handlers to matching elements. This handler can only be triggered once per element
ready()	Binds a function to the ready event of a document (when an HTML document is ready to use)
resize()	Triggers, or binds a function to the resize event of selected elements
scroll()	Triggers, or binds a function to the scroll event of selected elements
select()	Triggers, or binds a function to the select event of selected elements
submit()	Triggers, or binds a function to the submit event of selected elements
toggle()	Binds two or more functions to the toggle between for the click event for selected elements
trigger()	Triggers all events bound to the selected elements
triggerHandler()	Triggers all functions bound to a specified event for the selected elements
unbind()	Remove an added event handler from selected elements
undelegate()	Remove an event handler to selected elements, now or in the future
unload()	Triggers, or binds a function to the unload event of selected elements

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

$(document).ready(function(){

$("button").bind("click",function(){

$("p").slideToggle();

});

</script>

</head>

<body>

<p>This is a paragraph.</p>

<button>Click me!</button>

</body>

</html>

jQuery Effects

Hide, Show, Toggle, Slide, Fade, and Animate.

Examples

jQuery hide()
Demonstrates a simple jQuery hide() method.

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

$(document).ready(function(){

$("p").click(function(){

$(this).hide();

});

</script>

</head>

<body>

<p>If you click on me, I will disappear.</p>

<p>Click me away!</p>

<p>Click me too!</p>

</body>

</html>

jQuery hide()
Another hide() demonstration. How to hide parts of text.

<html>

<head>

$(document).ready(function(){

$(".ex .hide").click(function(){

$(this).parents(".ex").hide("slow");

});

</script>

div.ex

{

background-color:#e5eecc;

padding:7px;

border:solid 1px #c3c3c3;

}

</style>

</head>

<body>

<h3>Island Trading</h3>

<p>Contact: Helen Bennett<br />

Garden House Crowther Way<br />

London</p>

</div>

<h3>Paris spécialités</h3>

<p>Contact: Marie Bertrand<br />

265, Boulevard Charonne<br />

Paris</p>

</div>

</body>

</html>

jQuery slideToggle()
Demonstrates a simple slide panel effect.

<html>

<head>

$(document).ready(function(){

$(".flip").click(function(){

$(".panel").slideToggle("slow");

});

</script>

div.panel,p.flip

{

margin:0px;

padding:5px;

text-align:center;

background:#e5eecc;

border:solid 1px #c3c3c3;

}

div.panel

{

height:120px;

display:none;

}

</style>

</head>

<body>

<p>Because time is valuable, we deliver quick and easy learning.</p>

<p>At W3Schools, you can study everything you need to learn, in an accessible and handy format.</p>

</div>

<p class="flip">Show/Hide Panel</p>

</body>

</html>

jQuery fadeTo()
Demonstrates a simple jQuery fadeTo() method.

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

$(document).ready(function(){

$("button").click(function(){

$("div").fadeTo("slow",0.25);

});

</script>

</head>

<body>

<button>Click to Fade</button>

</div>

</body>

</html>

jQuery animate()
Demonstrates a simple jQuery animate() method.

<html>

<head>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">

$(document).ready(function(){

$("button").click(function(){

$("div").animate({height:300},"slow");

$("div").animate({width:300},"slow");

$("div").animate({height:100},"slow");

$("div").animate({width:100},"slow");

});

</script>

</head>

<body>

<button>Start Animation</button>

<br /><br />

<div style="background:#98bf21;height:100px;width:100px;position:relative">

</div>

</body>

</html>

jQuery Hide and Show

With jQuery, you can hide and show HTML elements with the hide() and show() methods:

<html>

<head>

$(document).ready(function(){

$("#hide").click(function(){

$("p").hide();

});

$("#show").click(function(){

$("p").show();

});

</script>

</head>

<body>

<p>If you click on the "Hide" button, I will disappear.</p>

</body>

</html>

Both hide() and show() can take the two optional parameters: speed and callback.
Syntax:
$(selector).hide(speed,callback)
$(selector).show(speed,callback)
The speed parameter specifies the speed of the hiding/showing, and can take the following values: "slow", "fast", "normal", or milliseconds:

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("p").hide(1000);

});

</script>

</head>

<body>

<p>This is a paragraph with little content.</p>

<p>This is another small paragraph.</p>

</body>

</html>

The callback parameter is the name of a function to be executed after the hide (or show) function completes. You will learn more about the callback parameter in the next chapter of this tutorial.

jQuery Toggle

The jQuery toggle() method toggles the visibility of HTML elements using the show() or hide() methods.

Shown elements are hidden and hidden elements are shown.

Syntax:

$(selector).toggle(speed,callback)

The speed parameter can take the following values: "slow", "fast", "normal", or milliseconds.

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("p").toggle();

});

</script>

</head>

<body>

<button>Toggle</button>

<p>This is a paragraph with little content.</p>

<p>This is another small paragraph.</p>

</body>

</html>

The callback parameter is the name of a function to be executed after the hide (or show) method completes.

jQuery Slide - slideDown, slideUp, slideToggle

The jQuery slide methods gradually change the height for selected elements.

jQuery has the following slide methods:

$(selector).slideDown(speed,callback)

$(selector).slideUp(speed,callback)

$(selector).slideToggle(speed,callback)

The speed parameter can take the following values: "slow", "fast", "normal", or milliseconds.

The callback parameter is the name of a function to be executed after the function completes.

slideDown() Example

<html>

<head>

$(document).ready(function(){

$(".flip").click(function(){

$(".panel").slideDown("slow");

});

</script>

div.panel,p.flip

{

margin:0px;

padding:5px;

text-align:center;

background:#e5eecc;

border:solid 1px #c3c3c3;

}

div.panel

{

height:120px;

display:none;

}

</style>

</head>

<body>

<p>Because time is valuable, we deliver quick and easy learning.</p>

<p>At W3Schools, you can study everything you need to learn, in an accessible and handy format.</p>

</div>

<p class="flip">Show Panel</p>

</body>

</html>

slideUp() Example

<html>

<head>

$(document).ready(function(){

$(".flip").click(function(){

$(".panel").slideUp("slow");

});

</script>

div.panel,p.flip

{

margin:0px;

padding:5px;

text-align:center;

background:#e5eecc;

border:solid 1px #c3c3c3;

}

div.panel

{

height:120px;

}

</style>

</head>

<body>

<p>Because time is valuable, we deliver quick and easy learning.</p>

<p>At W3Schools, you can study everything you need to learn, in an accessible and handy format.</p>

</div>

<p class="flip">Hide Panel</p>

</body>

</html>

slideToggle() Example

<html>

<head>

$(document).ready(function(){

$(".flip").click(function(){

$(".panel").slideToggle("slow");

});

</script>

div.panel,p.flip

{

margin:0px;

padding:5px;

text-align:center;

background:#e5eecc;

border:solid 1px #c3c3c3;

}

div.panel

{

height:120px;

display:none;

}

</style>

</head>

<body>

<p>Because time is valuable, we deliver quick and easy learning.</p>

<p>At W3Schools, you can study everything you need to learn, in an accessible and handy format.</p>

</div>

<p class="flip">Show/Hide Panel</p>

</body>

</html>

jQuery Fade - fadeIn, fadeOut, fadeTo

The jQuery fade methods gradually change the opacity for selected elements.

jQuery has the following fade methods:

$(selector).fadeIn(speed,callback)

$(selector).fadeOut(speed,callback)

$(selector).fadeTo(speed,opacity,callback)

The speed parameter can take the following values: "slow", "fast", "normal", or milliseconds.

The opacity parameter in the fadeTo() method allows fading to a given opacity.

The callback parameter is the name of a function to be executed after the function completes.

fadeTo() Example

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("div").fadeTo("slow",0.25);

});

</script>

</head>

<body>

<button>Click to Fade</button>

</div>

</body>

</html>

Try it yourself »

fadeOut() Example

<html>

<head>

$(document).ready(function(){

$("div").click(function(){

$(this).fadeOut(4000);

});

</script>

</head>

<body>

<div style="background:yellow;width:200px">CLICK ME AWAY!</div>

<p>If you click on the box above, it will be removed.</p>

</body>

</html>

Try it yourself »

jQuery Custom Animations

The syntax of jQuery's method for making custom animations is:

$(selector).animate({params},[duration],[easing],[callback])

The key parameter is params. It defines the CSS properties that will be animated. Many properties can be animated at the same time:

animate({width:"70%",opacity:0.4,marginLeft:"0.6in",fontSize:"3em"});

The second parameter is duration. It specifies the speed of the animation. Possible values are "fast", "slow", "normal", or milliseconds.

Example 1

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("div").animate({height:300},"slow");

$("div").animate({width:300},"slow");

$("div").animate({height:100},"slow");

$("div").animate({width:100},"slow");

});

</script>

</head>

<body>

<button>Start Animation</button>

</div>

</body>

</html>

Try it yourself »

Example 2

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("div").animate({left:"100px"},"slow");

$("div").animate({fontSize:"3em"},"slow");

});

</script>

</head>

<body>

<button>Start Animation</button>

<div style="background:#98bf21;height:100px;width:200px;position:relative">HELLO</div>

</body>

</html>

Try it yourself »

HTML elements are positioned static by default and cannot be moved.
To make elements moveable, set the CSS position property to fixed, relative or absolute.

jQuery Effects

Here are some examples of effect functions in jQuery:

Function	Description
$(selector).hide()	Hide selected elements
$(selector).show()	Show selected elements
$(selector).toggle()	Toggle (between hide and show) selected elements
$(selector).slideDown()	Slide-down (show) selected elements
$(selector).slideUp()	Slide-up (hide) selected elements
$(selector).slideToggle()	Toggle slide-up and slide-down of selected elements
$(selector).fadeIn()	Fade in selected elements
$(selector).fadeOut()	Fade out selected elements
$(selector).fadeTo()	Fade out selected elements to a given opacity
$(selector).animate()	Run a custom animation on selected elements

jQuery Effect Methods

The following table lists all the methods used to create animation effects.

Method	Description
animate()	Performs a custom animation (of a set of CSS properties) for selected elements
clearQueue()	Removes all queued functions for the selected element
delay()	Sets a delay for all queued functions for the selected element
dequeue()	Runs the next queued functions for the selected element
fadeIn()	Gradually changes the opacity, for selected elements, from hidden to visible
fadeOut()	Gradually changes the opacity, for selected elements, from visible to hidden
fadeTo()	Gradually changes the opacity, for selected elements, to a specified opacity
fadeToggle()
hide()	Hides selected elements
queue()	Shows the queued functions for the selected element
show()	Shows hidden selected elements
slideDown()	Gradually changes the height, for selected elements, from hidden to visible
slideToggle()	Toggles between slideUp() and slideDown() for selected elements
slideUp()	Gradually changes the height, for selected elements, from visible to hidden
stop()	Stops a running animation on selected elements
toggle()	Toggles between hide() and show(), or custom functions, for selected elements

jQuery Callback Functions

A callback function is executed after the current animation is 100% finished.

jQuery Callback Functions

A callback function is executed after the current animation (effect) is finished.

JavaScript statements are executed line by line. However, with animations, the next line of code can be run even though the animation is not finished. This can create errors.

To prevent this, you can create a callback function. The callback function will not be called until after the animation is finished.

jQuery Callback Example

Typical syntax: $(selector).hide(speed,callback)

The callback parameter is a function to be executed after the hide effect is completed:

Example with Callback

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("p").hide(1000,function(){

alert("The paragraph is now hidden");

});

</script>

</head>

<body>

<p>This is a paragraph with little content.</p>

</body>

</html>

Try it yourself »

Without a callback parameter, the alert box is displayed before the hide effect is completed:

Example without Callback

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("p").hide(1000);

alert("The paragraph is now hidden");

});

</script>

</head>

<body>

<p>This is a paragraph with little content.</p>

</body>

</html>

Try it yourself »

jQuery HTML Manipulation

jQuery contains powerful methods (functions) for changing and manipulating HTML elements and attributes.

Changing HTML Content

$(selector).html(content)

The html() method changes the contents (innerHTML) of matching HTML elements.

Example

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("p").html("W3Schools");

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

Try it yourself »

Adding HTML content

$(selector).append(content)
The append() method appends content to the inside of matching HTML elements.
$(selector).prepend(content)
The prepend() method "prepends" content to the inside of matching HTML elements.

Example

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("p").append(" <b>W3Schools</b>.");

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

Try it yourself »

$(selector).after(content)
The after() method inserts HTML content after all matching elements.
$(selector).before(content)
The before() method inserts HTML content before all matching elements.

Example

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("p").after(" W3Schools.");

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

Try it yourself »

jQuery HTML Manipulation Methods From This Page:

Function	Description
$(selector).html(content)	Changes the (inner) HTML of selected elements
$(selector).append(content)	Appends content to the (inner) HTML of selected elements
$(selector).after(content)	Adds HTML after selected elements

jQuery HTML Methods

The following table lists all the methods used to manipulate the DOM.

The methods below work for both HTML and XML documents. Exception: the html() method.

Method	Description
addClass()	Adds one or more classes (for CSS) to selected elements
after()	Inserts content after selected elements
append()	Inserts content at the end of (but still inside) selected elements
appendTo()	Inserts content at the end of (but still inside) selected elements
attr()	Sets or returns an attribute and value of selected elements
before()	Inserts content before selected elements
clone()	Makes a copy of selected elements
detach()	Removes (but keeps a copy of) selected elements
empty()	Removes all child elements and content from selected elements
hasClass()	Checks if any of the selected elements have a specified class (for CSS)
html()	Sets or returns the content of selected elements
insertAfter()	Inserts HTML markup or elements after selected elements
insertBefore()	Inserts HTML markup or elements before selected elements
prepend()	Inserts content at the beginning of (but still inside) selected elements
prependTo()	Inserts content at the beginning of (but still inside) selected elements
remove()	Removes selected elements
removeAttr()	Removes an attribute from selected elements
removeClass()	Removes one or more classes (for CSS) from selected elements
replaceAll()	Replaces selected elements with new content
replaceWith()	Replaces selected elements with new content
text()	Sets or returns the text content of selected elements
toggleClass()	Toggles between adding/removing one or more classes (for CSS) from selected elements
unwrap()	Removes the parent element of the selected elements
val()	Sets or returns the value attribute of the selected elements (form elements)
wrap()	Wraps specified HTML element(s) around each selected element
wrapAll()	Wraps specified HTML element(s) around all selected elements
wrapInner()	Wraps specified HTML element(s) around the content of each selected element

jQuery CSS Manipulation

jQuery css() Method

jQuery has one important method for CSS manipulation: css()

The css() method has three different syntaxes, to perform different tasks.

css(name) - Return CSS property value
css(name,value) - Set CSS property and value
css({properties}) - Set multiple CSS properties and values

Return CSS Property

Use css(name) to return the specified CSS property value of the FIRST matched element:

Example

<html>

<head>

$(document).ready(function(){

$("div").click(function(){

$("p").html($(this).css("background-color"));

});

</script>

</head>

<body>

<p>Click in the red box to return the background color.</p>

</body>

</html>

Try it yourself »

Set CSS Property and Value

Use css(name,value) to set the specified CSS property for ALL matched elements:

Example

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("p").css("background-color","yellow");

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

Try it yourself »

Set Multiple CSS Property/Value Pairs

Use css({properties}) to set one or more CSS property/value pairs for the selected elements:

Example

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("p").css({"background-color":"yellow","font-size":"200%"});

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

<button>Click me</button>

</body>

</html>

Try it yourself »

jQuery height() and width() Methods

jQuery has two important methods for size manipulation.

height()
width()

Size Manipulation Examples

The height() method sets the height of all matching elements:

Example

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("#div1").height("200px");

});

</script>

</head>

<body>

<div id="div1" style="background:yellow;height:100px;width:100px">HELLO</div>

<div style="background:yellow;height:100px;width:100px">W3SCHOOLS</div>

<button>Click me</button>

</body>

</html>

Try it yourself »

The width() method sets the width of all matching elements:

Example

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("#div2").width("300px");

});

</script>

</head>

<body>

<div style="background:yellow;height:100px;width:100px">HELLO</div>

<div id="div2" style="background:yellow;height:100px;width:100px">W3SCHOOLS</div>

<button>Click me</button>

</body>

</html>

Try it yourself »

jQuery CSS Methods From this Page:

CSS Properties	Description
$(selector).css(name)	Get the style property value of the first matched element
$(selector).css(name,value)	Set the value of one style property for matched elements
$(selector).css({properties})	Set multiple style properties for matched elements
$(selector).height(value)	Set the height of matched elements
$(selector).width(value)	Set the width of matched elements

jQuery CSS Methods

The following table lists all the methods used to manipulate CSS properties.

Method	Description
addClass()	Adds one or more classes to selected elements
css()	Sets or returns one or more style properties for selected elements
hasClass()	Checks if any of the selected elements have a specified class
height()	Sets or returns the height of selected elements
offset()	Sets or returns the position (relative to the document) for selected elements
offsetParent()	Returns the first parent element that is positioned
position()	Returns the position (relative to the parent element) of the first selected element
removeClass()	Removes one or more classes from selected elements
scrollLeft()	Sets or returns the horizontal position of the scrollbar for the selected elements
scrollTop()	Sets or returns the vertical position of the scrollbar for the selected elements
toggleClass()	Toggles between adding/removing one or more classes from selected elements
width()	Sets or returns the width of selected elements

jQuery AJAX

jQuery has a rich library of methods (functions) for AJAX development.

jQuery AJAX Example

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("div").load('test1.txt');

});

</script>

</head>

<body>

<div><h2>Let AJAX change this text</h2></div>

<button>Change Content</button>

</body>

</html>

Try it yourself »

What is AJAX?

AJAX = Asynchronous JavaScript and XML.

AJAX is a technique for creating fast and dynamic web pages.

AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page.

AJAX and jQuery

jQuery provides a rich set of methods for AJAX web development.

With jQuery AJAX, you can request TXT, HTML, XML or JSON data from a remote server using both HTTP Get and HTTP Post.

And you can load remote data directly into selected HTML elements of your web page!

Write Less, Do More

The jQuery load() method is a simple (but very powerful) AJAX function. It has the following syntax:

$(selector).load(url,data,callback)

Use the selector to define the HTML element(s) to change, and the url parameter to specify a web address for your data.

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$("div").load('test1.txt');

});

</script>

</head>

<body>

<div><h2>Let AJAX change this text</h2></div>

<button>Change Content</button>

</body>

</html>

Only if you want to send data to the server, you need to use the data parameter. Only if you need to trigger a function after completion, you will use the callback parameter.

Low Level AJAX

$.ajax(options) is the syntax of the low level AJAX function.

$.ajax offers more functionality than higher level functions like load, get, and post, but it is also more difficult to use.

The option parameter takes name|value pairs defining url data, passwords, data types, filters, character sets, timeout and error functions.

<html>

<head>

$(document).ready(function(){

$("button").click(function(){

$.ajax({url:"test1.txt", success:function(result){

$("div").html(result);

}});

});});

</script>

</head>

<body>

<div><h2>Let AJAX change this text</h2></div>

<button>Change Content</button>

</body>

</html>

Try it yourself »

jQuery AJAX Methods From This Page:

Request	Description
$(selector).load(url,data,callback)	Load remote data into selected elements
$.ajax(options)	Load remote data into an XMLHttpRequest object

jQuery AJAX Methods

AJAX is the art of exchanging data with a server, and update parts of a web page - without reloading the whole page.

The following table lists all the jQuery AJAX methods:

Method	Description
$.ajax()	Performs an AJAX request
ajaxComplete()	Specifies a function to run when the AJAX request completes
ajaxError()	Specifies a function to run when the AJAX request completes with an error
ajaxSend()	Specifies a function to run before the AJAX request is sent
$.ajaxSetup()	Sets the default values for future AJAX requests
ajaxStart()	Specifies a function to run when the first AJAX request begins
ajaxStop()	Specifies a function to run when all AJAX requests have completed
ajaxSuccess()	Specifies a function to run an AJAX request completes successfully
$.get()	Loads data from a server using an AJAX HTTP GET request
$.getJSON()	Loads JSON-encoded data from a server using a HTTP GET request
$.getScript()	Loads (and executes) a JavaScript from the a server using an AJAX HTTP GET request
load()	Loads data from a server and puts the returned HTML into the selected element
$.param()	Creates a serialized representation of an array or object (can be used as URL query string for AJAX requests)
$.post()	Loads data from a server using an AJAX HTTP POST request
serialize()	Encodes a set of form elements as a string for submission
serializeArray()	Encodes a set of form elements as an array of names and values

SIVANANDA REDDY GANGIREDDY

Pages

Friday, June 24, 2011

jQuery

jQuery Effects

jQuery Callback Functions

jQuery HTML Manipulation

Changing HTML Content

$(selector).html(content)

Example

Adding HTML content

Example

Example

jQuery HTML Manipulation Methods From This Page:

jQuery CSS Manipulation

jQuery AJAX

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