【推荐】50个JQuery代码技巧让你变成js高手(1)

1. 创建一个嵌套的过滤器

.filter(":not(:has(.selected))") //去掉所有不包含class为.selected的元素

2. 重用你的元素查询

var allItems = $("div.item");  
var keepList = $("div#container1 div.item"); 
<div>class names: 
$(formToLookAt + " input:checked").each(function() {     keepListkeepList = keepList.filter("." + $(this).attr("name")); });
</div>

3. 使用has()来判断一个元素是否包含特定的class或者元素

//jQuery 1.4.* includes support for the has method. This method will find  
//if a an element contains a certain other element class or whatever it is  
//you are looking for and do anything you want to them. 
$("input").has(".email").addClass("email_icon");

4. 使用jQuery切换样式

//Look for the media-type you wish to switch then set the href to your new style sheet  
$('link[media='screen']').attr('href', 'Alternative.css');  

5. 限制选择的区域

//Where possible, pre-fix your class names with a tag name  
//so that jQuery doesn't have to spend more time searching  
//for the element you're after. Also remember that anything  
//you can do to be more specific about where the element is  
//on your page will cut down on execution/search times  
var in_stock = $('#shopping_cart_items input.is_in_stock');

<ul id="shopping_cart_items">  
<li>  
<input value="Item-X" name="item" class="is_in_stock" type="radio"> Item X</li>  
<li>  
<input value="Item-Y" name="item" class="3-5_days" type="radio"> Item Y</li>  
<li>  
<input value="Item-Z" name="item" class="unknown" type="radio"> Item Z</li>  
</ul> 

6. 如何正确使用ToggleClass

//Toggle class allows you to add or remove a class  
//from an element depending on the presence of that  
//class. Where some developers would use:  
a.hasClass('blueButton') ? a.removeClass('blueButton') : a.addClass('blueButton');  
//toggleClass allows you to easily do this using  
a.toggleClass('blueButton'); 

7. 设置IE指定的功能

if ($.browser.msie) { // Internet Explorer is a sadist. } 

8. 使用jQuery来替换一个元素

$('#thatdiv').replaceWith('fnuh');

9. 验证一个元素是否为空

if ($('#keks').html()) { //Nothing found ;}  

10. 在无序的set中查找一个元素的索引

$("ul > li").click(function () {  
    var index = $(this).prevAll().length;  
});

11. 绑定一个函数到一个事件

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

12. 添加HTML到一个元素

$('#lal').append('sometext');

13. 创建元素时使用对象来定义属性

var e = $("", { href: "#", class: "a-class another-class", title: "..." });

14. 使用过滤器过滤多属性

//This precision-based approached can be useful when you use  
//lots of similar input elements which have different types  
var elements = $('#someid input[type=sometype][value=somevalue]').get(); 

15. 使用jQuery预加载图片

jQuery.preloadImages = function() { for(var i = 0; i').attr('src', arguments[i]); } };  
// Usage $.preloadImages('image1.gif', '/path/to/image2.png', 'some/image3.jpg');   

16. 设置任何匹配一个选择器的事件处理程序

$('button.someClass').live('click', someFunction);
  //Note that in jQuery 1.4.2, the delegate and undelegate options have been
  //introduced to replace live as they offer better support for context
    //For example, in terms of a table where before you would use..
  // .live()
  $("table").each(function(){
    $("td", this).live("hover", function(){
    $(this).toggleClass("hover");
    });
  });
  //Now use..
  $("table").delegate("td", "hover", function(){
  $(this).toggleClass("hover");
});

17. 找到被选择到的选项(option)元素

$('#someElement').find('option:selected');

18. 隐藏包含特定值的元素

$("p.value:contains('thetextvalue')").hide();

19. 自动的滚动到页面特定区域

jQuery.fn.autoscroll = function(selector) {
  $('html,body').animate(
    {scrollTop: $(selector).offset().top},
    500
  );
}
//Then to scroll to the class/area you wish to get to like this:
$('.area_name').autoscroll();

20. 检测各种浏览器

Detect Safari (if( $.browser.safari)),
Detect IE6 and over (if ($.browser.msie && $.browser.version > 6 )),
Detect IE6 and below (if ($.browser.msie && $.browser.version <= 6 )),
Detect FireFox 2 and above (if ($.browser.mozilla && $.browser.version >= '1.8' ))

21. 替换字符串中的单词

var el = $('#id');
el.html(el.html().replace(/word/ig, ''));

22. 关闭右键的菜单

$(document).bind('contextmenu',function(e){ return false; });

23. 定义一个定制的选择器

$.expr[':'].mycustomselector = function(element, index, meta, stack){
// element- is a DOM element
// index - the current loop index in stack
// meta - meta data about your selector
// stack - stack of all elements to loop
// Return true to include current element
// Return false to explude current element
};
// Custom Selector usage:
$('.someClasses:test').doSomething();

24. 判断一个元素是否存在

if ($('#someDiv').length) {//hooray!!! it exists...}

25. 使用jQuery判断鼠标的左右键点击

$("#someelement").live('click', function(e) {
    if( (!$.browser.msie && e.button == 0) || ($.browser.msie && e.button == 1) ) {
        alert("Left Mouse Button Clicked");
    }
    else if(e.button == 2)
        alert("Right Mouse Button Clicked");
});

（转载注明出处：[url=http://www.a9832.com]博彩网[/url][url=http://www.tswa.org]博彩通[/url]）