Knowing this can begin to play the power of jQuery (rpm)

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Link: http: //www.cnblogs.com/dolphinX/archive/2013/10/08/3347677.html

Due to the current jQuery so outsize, I believe I need explain what jQuery, the company code in the extensive use of jQuery, but I am looking found that some of the children's code for a problem, the children use only jQuery fur, just use id selectors with attr method, there are several animation, but if so, compared to its cost brought about, in fact, might as well not use, here are a few common methods jQuery, jQuery to make the power play, otherwise only a limited number of methods, with respect to the speed problem, really better without jQuery.

jQuery is so easy to use, and its use is compatible with the CSS selector syntax in obtaining the object of a great relationship, after all, we are familiar with CSS selectors (CSS selectors can look at about ten minutes to get CSS selectors ), but its powerful compatible CSS3 selectors, and even a lot more.

Selector

Once you have CSS selectors basis, see jQuery selector is very simple, not detailed them out

The basic selector
$(‘*’)	All elements matching page
$(‘#id’)	id selector
$(‘.class’)	Class selector
$(‘element’)	Tag selector

Composition / level selector
$(‘E,F’)	Multi-element selector, with "separated, while matching elements E or elements F
$(‘E F’)	Descendant selectors, separated by spaces, to match all elements of E progeny (not just the sub-elements, sub-elements down recursively) element F
$(E>F)	Child element selector, the ">" partition, all direct child elements matching element E
$(‘E+F’)	Directly adjacent to the selector, the matching element E after the adjacent of the sibling elements F
$(‘E~F’)	Normal adjacent selector (selector brother), matching element E after the sibling elements F (whether or not immediately adjacent)
$(‘.class1.class2’)	Match the class name contains both class1 and class2 contain elements
Basic filter selector
$("E:first")	First of all E
$("E:last")	All E in the last
$("E:not(selector)")	According to selector filter E
$("E:even")	All the index is even E
$("E:odd")	All the index is odd E
$("E:eq(n)")	All E is an element index of n
$("E:gt(n)")	E n in the index is greater than all the elements
$("E:ll(n)")	E n in the index is less than all of the elements
$(":header")	Select the element h1 ~ h7
$("div:animated")	Select executing animation elements
Content Filter
$(‘E:contains(value)’)	Value contained in the content of the element values
$(‘E:empty’)	Element content is empty
$(‘E:has(F)’)	Child element has elements of F, $ ( 'div: has (a)'): div a tag comprising
$(‘E: parent’)	The parent element is an element E, $ ( 'td: parent'): td element is the parent element
Visualization selector
$(‘E:hidden’)	All hidden E
$(‘E:visible’)	All visible E
Attribute filter selector
$ ( 'E [attr]')	E contains the attributes attr
$(‘E[attr=value]’)	Attributes attr = value of E
$(‘E[attr !=value]’)	Attribute attr! = Value of E
$(‘E[attr ^=value]’)	属性attr以value开头的E
$(‘E[attr $=value]’)	属性attr以value结尾的E
$(‘E[attr *=value]’)	属性attr包含value的E
$(‘E[attr][attr *=value]’)	可以连用
子元素过滤器
$(‘E:nth-child(n)’)	E的第n个子节点
$(‘E:nth-child(3n+1)’)	E的index符合3n+1表达式的子节点
$(‘E:nth-child(even)’)	E的index为偶数的子节点
$(‘E:nth-child(odd)’)	E的index为奇数的子节点
$(‘E:first-clild’)	所有E的第一个子节点
$(‘E:last-clild’)	所有E的最后一个子节点
$(‘E:only-clild’)	只有唯一子节点的E的子节点
表单元素选择器
$(‘E:type’)	特定类型的input
$(‘:checked’)	被选中的checkbox或radio
$(‘option: selected’)	被选中的option

筛选方法

.find(selector) 查找集合每个元素的子节点

Get the descendants(子节点) of each element in the current set of matched elements, filtered by a selector, jQuery object, or element.

$('li.item-ii').find('li').css('background-color', 'red');

.filter(selector) 过滤当前集合内元素

Reduce(减少) the set of matched elements to those that match the selector or pass the function's test.

$('li').filter(':even').css('background-color', 'red');

基本方法

.ready(handler) 文档加载完成后执行的方法，区别于window.onload

Specify a function to execute when the DOM is fully loaded.

$(document).ready(function() {
  // Handler for .ready() called.
});

.each(function(index,element)) 遍历集合内每个元素

Iterate over a jQuery object, executing a function for each matched element.

$("li" ).each(function( index ) {
  console.log( index + ": " + $(this).text() );
});

jQuery.extend( target [, object1 ] [, objectN ] ) 合并对象

Merge the contents of two or more objects together into the first object.

var object = $.extend({}, object1, object2);

获取元素

.eq(index) 按index获取jQuery对象集合中的某个特定jQuery对象

Reduce the set of matched elements to the one at the specified index.

.eq(-index) 按逆序index获取jQuery对象集合中的某个特定jQuery对象

An integer indicating the position of the element, counting backwards from the last element in the set.

$( "li" ).eq( 2 ).css( "background-color", "red" );

.get(index) 获取jQuery集合对象中某个特定index的DOM对象（将jQuery对象自动转换为DOM对象）

Retrieve one of the DOM elements matched by the jQuery object.

console.log( $( "li" ).get( -1 ) );

.get() 将jQuery集合对象转换为DOM集合对象并返回

Retrieve the DOM elements matched by the jQuery object.

console.log( $( "li" ).get() );

.index() / .index(selector)/ .index(element) 从给定集合中查找特定元素index

Search for a given element from among the matched elements.

1. 没参数返回第一个元素index

2.如果参数是DOM对象或者jQuery对象，则返回参数在集合中的index

3.如果参数是选择器，返回第一个匹配元素index，没有找到返回-1

var listItem = $( "#bar" );
alert( "Index: " + $( "li" ).index( listItem ) );

.clone（[withDataAndEvents][,deepWithDataAndEvents]) 创建jQuery集合的一份deep copy（子元素也会被复制），默认不copy对象的shuju和绑定事件

Create a deep copy of the set of matched elements.

$( ".hello" ).clone().appendTo( ".goodbye" );

.parent([selector]) 获取jQuery对象符合selector的父元素

Get the parent of each element in the current set of matched elements, optionally filtered by a selector.

$( "li.item-a" ).parent('ul').css( "background-color", "red" );

.parents([selector]) 获取jQuery对象符合选择器的祖先元素

Get the ancestors of each element in the current set of matched elements, optionally filtered by a selector.

$( "span.selected" ) .parents( "div" ) .css( "border", "2px red solid" )

插入元素

.append(content[,content]) / .append(function(index,html)) 向对象尾部追加内容

Insert content, specified by the parameter, to the end of each element in the set of matched elements.

1. 可以一次添加多个内容，内容可以是DOM对象、HTML string、 jQuery对象

2. 如果参数是function，function可以返回DOM对象、HTML string、 jQuery对象，参数是集合中的元素位置与原来的html值

$( ".inner" ).append( "<p>Test</p>" );
$( "body" ).append( $newdiv1, [ newdiv2, existingdiv1 ] );
$( "p" ).append( "<strong>Hello</strong>" );
$( "p" ).append( $( "strong" ) );
$( "p" ).append( document.createTextNode( "Hello" ) );

.appendTo(target) 把对象插入到目标元素尾部，目标元素可以是selector, DOM对象, HTML string, 元素集合,jQuery对象;

Insert every element in the set of matched elements to the end of the target.

$( "h2" ).appendTo( $( ".container" ) );
$( "<p>Test</p>" ).appendTo( ".inner" );

.prepend(content[,content]) / .prepend(function(index,html)) 向对象头部追加内容，用法和append类似

Insert content, specified by the parameter, to the beginning of each element in the set of matched elements.

$( ".inner" ).prepend( "<p>Test</p>" );

.prependTo(target) 把对象插入到目标元素头部，用法和prepend类似

Insert every element in the set of matched elements to the beginning of the target.

$( "<p>Test</p>" ).prependTo( ".inner" );

.before([content][,content]) / .before(function) 在对象前面(不是头部，而是外面，和对象并列同级)插入内容，参数和append类似

Insert content, specified by the parameter, before each element in the set of matched elements.

$( ".inner" ).before( "<p>Test</p>" );
$( ".container" ).before( $( "h2" ) );
$( "p" ).first().before( newdiv1, [ newdiv2, existingdiv1 ] );
$( "p" ).before( "<b>Hello</b>" );
$( "p" ).before( document.createTextNode( "Hello" ) );

.insertBefore(target) 把对象插入到target之前（同样不是头部，是同级）

Insert every element in the set of matched elements before the target.

$( "h2" ).insertBefore( $( ".container" ) );

.after([content][,content]) / .after(function（index）) 和before相反，在对象后面(不是尾部，而是外面，和对象并列同级)插入内容，参数和append类似

Insert content, specified by the parameter, after each element in the set of matched elements.

$( ".inner" ).after( "<p>Test</p>" );
$( "p" ).after( document.createTextNode( "Hello" ) );

.insertAfter(target) 和insertBefore相反，把对象插入到target之后（同样不是尾部，是同级）

Insert every element in the set of matched elements after the target.

$( "<p>Test</p>" ).insertAfter( ".inner" );
$( "p" ).insertAfter( "#foo" );

包裹元素

.wrap(wrappingElement) / .wrap(function(index)) 为每个对象包裹一层HTML结构，可以是selector, element, HTML string, jQuery object

Wrap an HTML structure around each element in the set of matched elements.

<div class="container">
  <div class="inner">Hello</div>
  <div class="inner">Goodbye</div>
</div>

$( ".inner" ).wrap( "<div class='new'></div>" );

<div class="container">
  <div class="new">
    <div class="inner">Hello</div>
  </div>
  <div class="new">
    <div class="inner">Goodbye</div>
  </div>
</div>

.wrapAll(wrappingElement) 把所有匹配对象包裹在同一个HTML结构中

Wrap an HTML structure around all elements in the set of matched elements.

<div class="container">
  <div class="inner">Hello</div>
  <div class="inner">Goodbye</div>
</div>

$( ".inner" ).wrapAll( "<div class='new' />");

<div class="container">
  <div class="new">
    <div class="inner">Hello</div>
    <div class="inner">Goodbye</div>
  </div>
</div>

.wrapInner(wrappingElement) / .wrapInner(function(index)) 包裹匹配元素内容，这个不好说，一看例子就懂

Wrap an HTML structure around the content of each element in the set of matched elements.

<div class="container">
  <div class="inner">Hello</div>
  <div class="inner">Goodbye</div>
</div>

$( ".inner" ).wrapInner( "<div class='new'></div>");

<div class="container">
  <div class="inner">
    <div class="new">Hello</div>
  </div>
  <div class="inner">
    <div class="new">Goodbye</div>
  </div>
</div>

.unwap() 把DOM元素的parent移除

Remove the parents of the set of matched elements from the DOM, leaving the matched elements in their place.

pTags = $( "p" ).unwrap();

属性方法

.val() 获取元素的value值

Get the current value of the first element in the set of matched elements.

$( "input:checkbox:checked" ).val();

.val(value) /.val(function(index,value)) 为元素设置值，index和value同样是指在为集合中每个元素设置的时候该元素的index和原value值

Set the value of each element in the set of matched elements.

$( "input" ).val( ‘hello’ );
$( "input" ).on( "blur", function() {
  $( this ).val(function( i, val ) {
    return val.toUpperCase();
  });
});

.attr(attributeName) 获取元素特定属性的值

Get the value of an attribute for the first element in the set of matched elements.

var title = $( "em" ).attr( "title" );

.attr(attributeName,value) / .attr(attributesJson) / .attr( attributeName, function(index, attr) ) 为元素属性赋值

Set one or more attributes for the set of matched elements.

$( "#greatphoto" ).attr( "alt", "Beijing Brush Seller" );

$( "#greatphoto" ).attr({
  alt: "Beijing Brush Seller",
  title: "photo by Kelly Clark"
});

$( "#greatphoto" ).attr( "title", function( i, val ) {
  return val + " - photo by Kelly Clark";
});

.prop( propertyName ) 获取元素某特性值

Get the value of a property for the first element in the set of matched elements.

$( elem ).prop( "checked" )

.prop(propertyName,value) / .prop(propertiesJson) / .prop(propertyName,function(index,oldPropertyValue)) 为元素特性赋值

Set one or more properties for the set of matched elements.

$( "input" ).prop( "checked", true );

$( "input[type='checkbox']" ).prop( "checked", function( i, val ) {
  return !val;
});

$( "input[type='checkbox']" ).prop({
  disabled: true
});

关于attribute 和 property区别可以看看 jQuery的attr与prop

.data(key,value) / .value(json) 为HTML DOM元素添加数据，HTML5元素已有data-*属性

Store arbitrary data associated with the matched elements.The .data() method allows us to attach data of any type to DOM elements in a way that is safe from circular references and therefore from memory leaks.

$( "body" ).data( "foo", 52 );
$( "body" ).data( "bar", { myType: "test", count: 40 } );
$( "body" ).data( { baz: [ 1, 2, 3 ] } );

.data(key) / .data() 获取获取data设置的数据或者HTML5 data-*属性中的数据

Return the value at the named data store for the first element in the jQuery collection, as set by data(name, value) or by an HTML5 data-* attribute.

alert( $( "body" ).data( "foo" ) );
alert( $( "body" ).data() );

alert( $( "body" ).data( "foo" ) ); // undefined
$( "body" ).data( "bar", "foobar" );
alert( $( "body" ).data( "bar" ) ); // foobar

CSS方法

.hasClass(calssName) 检查元素是否包含某个class，返回true/false

Determine whether any of the matched elements are assigned the given class.

$( "#mydiv" ).hasClass( "foo" )

.addClass(className) / .addClass(function(index,currentClass)) 为元素添加class，不是覆盖原class，是追加，也不会检查重复

Adds the specified class(es) to each of the set of matched elements.

$( "p" ).addClass( "myClass yourClass" );

$( "ul li" ).addClass(function( index ) {
  return "item-" + index;
});

removeClass([className]) / ,removeClass(function(index,class)) 移除元素单个/多个/所有class

Remove a single class, multiple classes, or all classes from each element in the set of matched elements.

$( "p" ).removeClass( "myClass yourClass" );

$( "li:last" ).removeClass(function() {
  return $( this ).prev().attr( "class" );
});

.toggleClass(className) /.toggleClass(className,switch) / .toggleClass([switch]) / .toggleClass( function(index, class, switch) [, switch ] ) toggle是切换的意思，方法用于切换，switch是个bool类型值，这个看例子就明白

Add or remove one or more classes from each element in the set of matched elements, depending on either the class's presence or the value of the switch argument.

<div class="tumble">Some text.</div>

第一次执行

$( "div.tumble" ).toggleClass( "bounce" )

<div class="tumble bounce">Some text.</div>

第二次执行

$( "div.tumble" ).toggleClass( "bounce" )

<div class="tumble">Some text.</div>

$( "#foo" ).toggleClass( className, addOrRemove );

// 两种写法意思一样

if ( addOrRemove ) {
  $( "#foo" ).addClass( className );
} else {
  $( "#foo" ).removeClass( className );
}

$( "div.foo" ).toggleClass(function() {
  if ( $( this ).parent().is( ".bar" ) ) {
    return "happy";
  } else {
    return "sad";
  }
});

.css(propertyName) / .css(propertyNames) 获取元素style特定property的值

Get the value of style properties for the first element in the set of matched elements.

var color = $( this ).css( "background-color" );

 var styleProps = $( this ).css([
    "width", "height", "color", "background-color"
  ]);

.css(propertyName,value) / .css( propertyName, function(index, value) ) / .css( propertiesJson ) 设置元素style特定property的值

Set one or more CSS properties for the set of matched elements.

$( "div.example" ).css( "width", function( index ) {
  return index * 50;
});

$( this ).css( "width", "+=200" );


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

   $( this ).css({
      "background-color": "yellow",
      "font-weight": "bolder"
    });

事件方法

.bind( eventType [, eventData ], handler(eventObject) ) 绑定事件处理程序，这个经常用，不多解释

Attach a handler to an event for the elements.

$( "#foo" ).bind( "click", function() {
  alert( "User clicked on 'foo.'" );
});

.delegate( selector, eventType, handler(eventObject) ) 这个看官方解释吧

Attach a handler to one or more events for all elements that match the selector, now or in the future, based on a specific set of root elements.

$( "table" ).on( "click", "td", function() {//这样把td的click事件处理程序绑在table上
  $( this ).toggleClass( "chosen" );
});

.on( events [, selector ] [, data ], handler(eventObject) ) 1.7后推荐使用，取代bind、live、delegate

Attach an event handler function for one or more events to the selected elements.

$( "#dataTable tbody" ).on( "click", "tr", function() {
  alert( $( this ).text() );
});

关于bind、live、delegate、on的区别可以看看 jQuery三种事件绑定方式.bind(),.live(),.delegate()

.trigger( eventType [, extraParameters ] ) JavaScript出发元素绑定事件

Execute all handlers and behaviors attached to the matched elements for the given event type.

$( "#foo" ).trigger( "click" );

.toggle( [duration ] [, complete ] ) / .toggle( options ) 隐藏或显示元素

Display or hide the matched elements.

$( ".target" ).toggle();

$( "#clickme" ).click(function() {
  $( "#book" ).toggle( "slow", function() {
    // Animation complete.
  });
});

动画/Ajax

这两部分内容比较多，不是简单的一个function就可以的，这里只是列举一下常用方法名，关于其使用可以看看 jQuery API animation ajax ，或者 jQuery的动画处理总结，ASP.NET 使用Ajax

动画

queue/dequeue/clearQueue

delay/stop

fadeIn/fadeOut/fadeTo/fadeToggle

slideUp/slideDown/slideToggle

show/hide

Ajax

$.ajax

$.load

$.get

最后

Understanding of the content above, using jQuery web development when you can experience the power of jQuery. This is not jQuery study guide, just a common method of introduction, if you want to learn jQuery, best textbooks or jQuery API , with examples in this article come from English to explain all the jQuery API. In addition paper introduces jQuery content is far from all, but first mastered these can have a more comprehensive understanding of jQuery, and then learn from other content when you can be getting.

Reproduced in: https: //my.oschina.net/garyun/blog/602717