JavaScript实现淘宝星级评分效果：从错误到数组优化的思路

初始方案与问题分析

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <script language="JavaScript" type="text/javascript">
 function star(n)
 {
  var array=new Array();
  array[0]=document.getElementById("oneStar");
  array[1]=document.getElementById("twoStar");
  array[2]=document.getElementById("threeStar");
  array[3]=document.getElementById("fourStar");
  array[4]=document.getElementById("fiveStar");
  for(var i=0;i<=n;i++)
  {
  array[i].innerText="★";
  }
  for( var j=4;j>n;j--)
  {
  array[j].innerText="☆";
  }
  document.getElementById("evaluate").innerText="您的评价是"+(n+1)+"星";
 }
 </script>
 <title>评星</title>
</head>
<body>
<strong>请您对我们作出评价:</strong>
<span id="star">
 <span style="cursor: pointer " onclick="star(0)"id="oneStar" >☆</span>
 <span style="cursor: pointer " onclick="star(1)" id="twoStar" >☆</span>
 <span style="cursor: pointer " onclick="star(2)" id="threeStar" >☆</span>
 <span style="cursor: pointer " onclick="star(3)" id="fourStar" >☆</span>
 <span style="cursor: pointer " onclick="star(4)" id="fiveStar" >☆</span>
</span><span id="evaluate"></span>

</body>
</html>

 for(var i=0;i<=n;i++)
  {
  document.getElementById("fiveStar").innerText="★";
  }
  for( var j=4;j>n;j--)
  {
  document.getElementById("fiveStar").innerText="☆";
  }

数组优化与最终成品

<!DOCTYPE html>
<head>
 <meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
 <title>淘宝评分效果</title>
 <style type="text/css">
 ul, li {margin: 0; padding: 0; border: 0;}
 .shop-rating {
  height: 25px;
  overflow: hidden;
  zoom: 1;
  padding: 2px 0;
  position: relative;
  z-index: 999;
  font:12px Arial;
  color:#000;
  line-height:1.2em
 }
 .shop-rating span {
  height: 23px;
  display: block;
  line-height: 23px;
  float: left;
 }
 .shop-rating span.title {
  width: 125px;
  text-align: right;
  margin-right: 5px;
 }
 .shop-rating ul {
  float: left;
 }
 .shop-rating .result {
  margin-left: 20px;
  padding-top: 2px;
 }
 .shop-rating .result span {
  color: #ff6d02;
 }
 .rating-level,
 .rating-level a {
  background: url(//img.jbzj.com/demoimg/201007/o_star.png) no-repeat scroll 1000px 1000px;
 }
 .rating-level {
  background-position: 0px 0px;
  width: 120px;
  height: 23px;
  position: relative;
  z-index: 1000;
 }
 .shop-rating .result em {
  color: #f60;
  font-family: arial;
  font-weight: bold;
 }
 .rating-level li {
  display: inline;
 }
 .rating-level a {
  line-height: 23px;
  height: 23px;
  position: absolute;
  top: 0px;
  left: 0px;
  text-indent: -999em;
  *zoom: 1;
  outline: none;
 }
 .rating-level a.one-star {
  width: 20%;
  z-index: 6;
 }
 .rating-level a.two-stars {
  width: 40%;
  z-index: 5;
 }
 .rating-level a.three-stars {
  width: 60%;
  z-index: 4;
 }
 .rating-level a.four-stars {
  width: 80%;
  z-index: 3;
 }
 .rating-level a.five-stars {
  width: 100%;
  z-index: 2;
 }
 .rating-level .current-rating, .rating-level a:hover {background-position:0 -28px}
 .rating-level a.one-star:hover,.rating-level a.two-stars:hover,.rating-level a.one-star.current-rating,.rating-level a.two-stars.current-rating{background-position:0 -116px;}
 .rating-level .three-stars .current-rating,.rating-level .four-stars .current-rating,.rating-level .five-stars .current-rating{background-position:0 -28px;}
 </style>
</head>
<body>
<div class="shop-rating">
 <span class="title">你对我人品的评价:</span>
 <ul class="rating-level" id="stars2">
 <li><a href="javascript:void(0);" class="one-star" star:value="20">20</a></li>
 <li><a href="javascript:void(0);" class="two-stars" star:value="40">40</a></li>
 <li><a href="javascript:void(0);" class="three-stars" star:value="60">60</a></li>
 <li><a href="javascript:void(0);" class="four-stars" star:value="80">80</a></li>
 <li><a href="javascript:void(0);" class="five-stars" star:value="100">100</a></li>
 </ul>
 <span id="stars2-tips" class="result"></span>
 <input type="hidden" id="stars2-input" name="b" value="" size="2" />
</div>
<script>
 var TB = function() {
 var T$ = function(id) { return document.getElementById(id) }
 var T$$ = function(r, t) { return (r || document).getElementsByTagName(t) }
 var Stars = function(cid, rid, hid, config) {
  var lis = T$$(T$(cid), 'li'), curA;
  for (var i = 0, len = lis.length; i < len; i++) {
  lis[i]._val = i;
  lis[i].onclick = function() {
   T$(rid).innerHTML = '<em>' + (T$(hid).value = T$$(this, 'a')[0].getAttribute('star:value')) + '分</em> - ' + config.info[this._val];
   curA = T$$(T$(cid), 'a')[T$(hid).value / config.step - 1];
  };
  lis[i].onmouseout = function() {
   curA && (curA.className += config.curcss);
  }
  lis[i].onmouseover = function() {
   curA && (curA.className = curA.className.replace(config.curcss, ''));
  }
  }
 };
 return {Stars: Stars}
 }().Stars('stars2', 'stars2-tips', 'stars2-input', {
 'info' : ['人品极差', '人品不咋地', '人品一般吧', '人品不错', '人品极好啊'],
 'curcss': ' current-rating',
 'step': 20
 });
</script>
</body>
</html>