jQuery里提供了许多创建交互式网站的方法，在开发Web项目时，开发人员应该好好利用jQuery代码，它们不仅能给网站带来各种动画、特效，还会提高网站的用户体验。

本文收集了10段非常实用的jQuery代码片段，你可以直接复制黏贴到代码里，但请开发者注意了，要理解代码再使用哦。下面就让我们一起来享受jQuery代码的魅力之处吧。

1.预加载图片

(function($) {     var cache = [];        // Arguments are image paths relative to the current page.     $.preLoadImages = function() {       var args_len = arguments.length;       for (var i = args_len; i--;) {         var cacheImage = document.createElement('img');         cacheImage.src = arguments[i];         cache.push(cacheImage);       }     }   jQuery.preLoadImages("image1.gif", "/path/to/image2.png");

2. 让页面中的每个元素都适合在移动设备上展示

var scr = document.createElement('script');   scr.setAttribute('src', 'https://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js');   document.body.appendChild(scr);   scr.onload = function(){       $('div').attr('class', '').attr('id', '').css({           'margin' : 0,           'padding' : 0,           'width': '100%',           'clear':'both'       });   };

3.图像等比例缩放

$(window).bind("load", function() {          // IMAGE RESIZE       $('#product_cat_list img').each(function() {           var maxWidth = 120;           var maxHeight = 120;           var ratio = 0;           var width = $(this).width();           var height = $(this).height();           if(width > maxWidth){               ratio = maxWidth / width;               $(this).css("width", maxWidth);               $(this).css("height", height * ratio);               height = height * ratio;           }           var width = $(this).width();           var height = $(this).height();           if(height > maxHeight){               ratio = maxHeight / height;               $(this).css("height", maxHeight);               $(this).css("width", width * ratio);               width = width * ratio;           }       });          //$("#contentpage img").show();          // IMAGE RESIZE   });

4.返回页面顶部

// Back To Top   $(document).ready(function(){     $('.top').click(function() {         $(document).scrollTo(0,500);      });   });   //Create a link defined with the class .top   Back To Top

5.使用jQuery打造手风琴式的折叠效果

var accordion = {        init: function(){              var $container = $('#accordion');              $container.find('li:not(:first) .details').hide();              $container.find('li:first').addClass('active');              $container.on('click','li a',function(e){                     e.preventDefault();                     var $this = $(this).parents('li');                     if($this.hasClass('active')){                            if($('.details').is(':visible')) {                                   $this.find('.details').slideUp();                            } else {                                   $this.find('.details').slideDown();                            }                     } else {                            $container.find('li.active .details').slideUp();                            $container.find('li').removeClass('active');                            $this.addClass('active');                            $this.find('.details').slideDown();                     }              });        }   };

6.通过预加载图片廊中的上一幅下一幅图片来模仿Facebook的图片展示方式

var nextimage = "/images/some-image.jpg";   $(document).ready(function(){   window.setTimeout(function(){   var img = $("").attr("src", nextimage).load(function(){   //all done   });   }, 100);   });

7.使用jQuery和Ajax自动填充选择框

$(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 += '   ' + j[i].optionDisplay + '   ';   }   $("select#ctlPerson").html(options);   })   })   })

8.自动替换丢失的图片

// Safe Snippet   $("img").error(function () {       $(this).unbind("error").attr("src", "missing_image.gif");   });   // Persistent Snipper   $("img").error(function () {       $(this).attr("src", "missing_image.gif");   });

9.在鼠标悬停时显示淡入/淡出特效

$(document).ready(function(){       $(".thumbs img").fadeTo("slow", 0.6);   // This sets the opacity of the thumbs to fade down to 60% when the page loads       $(".thumbs img").hover(function(){           $(this).fadeTo("slow", 1.0);   // This should set the opacity to 100% on hover       },function(){           $(this).fadeTo("slow", 0.6);   // This should set the opacity back to 60% on mouseout       });   });

10.清空表单数据

function clearForm(form) {        // iterate over all of the inputs for the form        // element that was passed in     $(':input', form).each(function() {       var type = this.type;       var tag = this.tagName.toLowerCase();   // normalize case          // it's ok to reset the value attr of text inputs,          // password inputs, and textareas       if (type == 'text' || type == 'password' || tag == 'textarea')         this.value = "";       // checkboxes and radios need to have their checked state cleared       // but should *not* have their 'value' changed       else if (type == 'checkbox' || type == 'radio')         this.checked = false;       // select elements need to have their 'selectedIndex' property set to -1       // (this works for both single and multiple select elements)       else if (tag == 'select')         this.selectedIndex = -1;     });   };