有时候你需要提示用户目前操作的输入框，你可以使用下面代码高亮显示标示：

$("form :input").focus(function() { $("label[for='" + this.id + "']").addClass("labelfocus"); }).blur(function() { $("label").removeClass("labelfocus"); });

18. 动态方式添加表单元素

这个方法可以帮助你动态的添加表单中的元素，比如，input等：

//change event on password1 field to prompt new input $('#password1').change(function() { //dynamically create new input and insert after password1 $("#password1").append("<input type='text' name='password2' id='password2' />"); });

19. 自动将数据导入selectbox中

下面代码能够使用ajax数据自动生成选择框的内容

$(function(){ $("select#ctlJob").change(function(){ $.getJSON("/select.php",{id: $(this).val(), ajax: 'true'}, function(j){ var options = ''; for (var i = 0; i < j.length; i++) { options += '<option value="' + j[i].optionValue + '">' + j[i].optionDisplay + '</option>'; } $("select#ctlPerson").html(options); }) }) })

20.判断一个复选框是否被选中

代码很简单，如下：

$('#checkBox').attr('checked');

21. 使用代码来递交表单

代码很简单，如下：

$("#myform").submit();

22. 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

23. 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>

24. 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");

25. 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');

26. 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>

27. 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');

28. 设置IE指定的功能

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

29. 使用jQuery来替换一个元素

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

30. 验证一个元素是否为空

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

31. 在无序的set中查找一个元素的索引

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

32. 绑定一个函数到一个事件

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

33. 添加HTML到一个元素

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

34. 创建元素时使用对象来定义属性

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

35. 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();

36. 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');