JavaScript制作淘宝星级评分效果的思路

小编也是刚开始学JavaScript，觉得淘宝评星效果很棒，于是产生了自己写一个的想法，先给大家分享一下实现效果：

现附上自己写的源代码

<!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>

一开始的时候用了两个for循环就是这样的:

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

大神们估计已经看出来了,在for循环之后HTML里的span已经失去了作用,也就是说它只能评价一次.....
于是顺着这个思路想到了用数组解决这个问题,就是让评星效果里的每一颗星储存到数组里,写出了上述的代码,可楼主还犯了一个小错误,着实困恼了许久....
array[0]=document.getElementById("oneStar").innerText;
通过这样定义的数组....结果可想而知,后面的代码根本无法改变评星,后来意识到,这样的定义直接将ID为onestar的元素的内容赋值给了数组,也就是说数组成了一个指向数组的指针....自然无法改变对应元素的值.后来总算明白了....
之后又加了一些CSS效果
成品是这样的:

<!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(http://zsrimg.ikafan.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>

以上就是JavaScript制作淘宝星级评分效果的思路，语言很直白，易理解，希望对大家的学习有所帮助，和小编一起去探索javascript更多的神奇之处，共同进步。