提取字符串——练习

此为一个JavaScript提取字符串的练习。

code:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>提取关键词</title>
<script language="JavaScript">
<!--
function Get_Keywords(){

    var oForm = document.forms["form1"];
    var tmp = oForm.Title.value;

    if (tmp == ""){
        alert("请输入标题。");
        return false;
    }

    var kk = "";
    var tt = "";
    var i=0;
    var j = 0;

    for (j=0;j<tmp.length-1 ;j++ )
    {
        tt = tmp.substring(i,i+2);  //提取2个字符
        if (kk.indexOf(tt) == -1)   //tt在KK搜索不到位置
            kk = kk + "|" + tt;
        i = i+1;
    }

    oForm.Keywords.value = kk.substring(1,kk.length);  
    //kk.length返回字符串形式是：|北京|京早|**
    //起始位置1，就是从：北京**开始
    //起始位置0，就是从：|**开始

}
//-->
</script>
</head>

<body>
<form id="form1" name="form1" method="post" action="">
  <table width="600" border="0" align="center" cellpadding="6" cellspacing="0">
    <tr>
      <td align="center">标题</td>
      <td><label>
        <input name="Title" type="text" id="Title" size="50" maxlength="50" />
      </label></td>
    </tr>
    <tr>
      <td align="center">关键词</td>
      <td><label>
        <input name="Keywords" type="text" id="Keywords" size="50" maxlength="255" /> <a href="###" onClick="Get_Keywords();">自动提取</a>
      </label></td>
    </tr>
    <tr>
      <td> </td>
      <td><label>
        <input type="submit" name="Submit" value="提交" />
        <input type="reset" name="Submit2" value="重置" />
      </label></td>
    </tr>
  </table>
</form>
</body>
</html>

示图如下：

 

posted @ 2012-12-06 16:31  ChuanYue  阅读(149)  评论(0)  编辑  收藏  举报