Getting Started with jquery

Getting Started with jquery

before learning jquery, look at HTML, CSS, JavaScript.

jquery is a library of JavaScript functions

Mainly include:

1.HTML element Extraction

2.HTML element operation

3.CSS operation

4.JavaScript Effects and animations

5.HTML DOM Traversal and modification

6.AJAX

7.Utilities

First, how to use jquery in HTML

Add a script tag to the head in the page

<script type= "Text/javascript" src= "Jquery.js" ></script>

<script type= "Text/javascript" src= "Jquery.js" ></script>

Second, the most distinctive features of jquery

$ is one of the obvious features of jquery. Its basic usage: $ (selector). Action ()

(1) selector a bit like DOM parsing.

(2) Action is the response event.

Third, jquery selector

(1) using CSS to extract HTML elements

Extract tags for all "p" in HTML: $ ("P")

Extract the label for "P" in a class in HTML: $ ("P.class")

Extract the first tag with "P" in the HTML ID as Demo: # ("P#demo")

(2) using XPath to extract the elements of a given property

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

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

$ ("[href!= ' # ']") selects all elements with an HREF value that is not equal to "#".

$ ("[href$= '. jpg ']") selects all elements with an href value ending with ". jpg".

Iv. Responding to Events

$ ("label"). Click (function () {... some code ...})

(1) in the head of the HTML

<script type= "Text/javascript" src= "Jquery.js" ></script>

<script type= "Text/javascript" >

$ (document). Ready (function () {

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

... some code ...

 });

});

</script>

(2) in a separate JS

<script type= "Text/javascript" src= "Jquery.js" ></script>

<script type= "Text/javascript" src= "My_jquery_functions.js" ></script>

Note: jquery name conflicts

jquery uses the $ symbol as a way to profile jquery.

functions in some other JavaScript libraries, such as Prototype, also use the $ notation.

JQuery uses a method called noconflict () to resolve the problem.

var jq=jquery.noconflict (), which helps you to use your own name (such as JQ) instead of the $ symbol.

V. Event functions

Common events: Hide, show, toggle, swipe, and animate

Getting Started with jquery