JavaScript製作淘寶星級評等效果的思路_javascript技巧

小編也是剛開始學JavaScript，覺得淘寶評星效果很棒，於是產生了自己寫一個的想法，先給大家分享一下實現效果：

現附上自己寫的原始碼

<!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="您的評價是"+(n+1)+"星";  } </script> <title>評星</title></head><body><strong>請您對我們作出評價:</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>

一開始的時候用了兩個for迴圈就是這樣的:

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

大神們估計已經看出來了,在for迴圈之後HTML裡的span已經失去了作用,也就是說它只能評價一次.....
於是順著這個思路想到了用數組解決這個問題,就是讓評星效果裡的每一顆星儲存到數組裡,寫出了上述的代碼,可樓主還犯了一個小錯誤,著實困惱了許久....
array[0]=document.getElementById("oneStar").innerText;
通過這樣定義的數組....結果可想而知,後面的代碼根本無法改變評星,後來意識到,這樣的定義直接將ID為onestar的元素的內容賦值給了數組,也就是說數組成了一個指向數組的指標....自然無法改變對應元素的值.後來總算明白了....
之後又加了一些CSS效果
成品是這樣的:

<!DOCTYPE html><head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> <title>淘寶評分效果</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://files.jb51.net/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">你對我人品的評價:</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' : ['人品極差', '人品不咋地', '人品一般吧', '人品不錯', '人品極好啊'],  'curcss': ' current-rating',  'step': 20 });</script></body></html>

以上就是JavaScript製作淘寶星級評等效果的思路，語言很直白，易理解，希望對大家的學習有所協助，和小編一起去探索javascript更多的神奇之處，共同進步。