JavaScript统计字符串中每个字符出现次数的完整实例

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<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <title>求字符串中每个字符出现的次数 </title>
  <script type="text/javascript">
    var str = "abdcadfasfdbadfafdasdfasyweroweurowqrewqrwqrebwqrewqrejwq;;";
    var array = str.split("");
    array.sort();
    var countArray = [];
    var CountObj = function(character){
      this.count = 1
      this.character = character;
      return this;
    }
    var arrayObj = null,
      countArrayObj = null,
      arrayLength = 0;
    for (var i = 0, length = array.length; i < length; i++) {
      arrayObj = array[i];
      arrayLength = countArray.length;
      if (arrayLength > 0) {
        countArrayObj = countArray[arrayLength - 1];
        if (countArrayObj.character == arrayObj) {
          countArrayObj.count = countArrayObj.count + 1;
        } else {
          countArray.push(new CountObj(arrayObj));
        }
      } else {
        countArray.push(new CountObj(arrayObj));
      }
    }
    /**
     * 输出每个字母和其对应出现的统计数据
     */
    for(var i=0,length=countArray.length; i<length; i++) {
      countArrayObj = countArray[i];
      console.log(countArrayObj.character + ":" + countArrayObj.count);
    }
  </script>
</head>
<body>
</body>
</html>