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  • js 操作select和option

    js 操作select和option

    1.动态创建select

         function createSelect(){

      var mySelect = document.createElement_x("select");
              mySelect.id = "mySelect"; 
              document.body.appendChild(mySelect);
          }

    2.添加选项option

         function addOption(){

              //根据id查找对象,
               var obj=document.getElementByIdx_x('mySelect');

               //添加一个选项
    obj.add(new Option("文本","值"));    //这个只能在IE中有效
             obj.options.add(new Option("text","value")); //这个兼容IE与firefox
         }

    3.删除所有选项option

         function removeAll(){
               var obj=document.getElementByIdx_x('mySelect');
    obj.options.length=0;

         }

    4.删除一个选项option

    function removeOne(){
               var obj=document.getElementByIdx_x('mySelect');

               //index,要删除选项的序号,这里取当前选中选项的序号

      var index=obj.selectedIndex;
      obj.options.remove(index);
         }

    5.获得选项option的值

      var obj=document.getElementByIdx_x('mySelect');

      var index=obj.selectedIndex; //序号,取当前选中选项的序号

      var val = obj.options[index].value;

    6.获得选项option的文本

      var obj=document.getElementByIdx_x('mySelect');

      var index=obj.selectedIndex; //序号,取当前选中选项的序号

      var val = obj.options[index].text;

    7.修改选项option

      var obj=document.getElementByIdx_x('mySelect');

      var index=obj.selectedIndex; //序号,取当前选中选项的序号

      var val = obj.options[index]=new Option("新文本","新值");

    8.删除select

          function removeSelect(){
                var mySelect = document.getElementByIdx_x("mySelect");
        mySelect.parentNode.removeChild(mySelect);
         }

    整个实例的完整代码如下:

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//ZH-CN" "http://www.w3.org/TR/html4/strict.dtd">
    <html>
    <head>
       <meta http-equiv="Content-Type" content="text/html">
    <head>
       <script language=JavaScript>
        function $(id)
        {
         return document.getElementByIdx_x(id)
        }
        function show()
        {
         var selectObj=$("area")
         var myOption=document.createElement_x("option")
         myOption.setAttribute("value","10")
         myOption.appendChild(document.createTextNode("上海"))
         var myOption1=document.createElement_x("option")
         myOption1.setAttribute("value","100")
         myOption1.appendChild(document.createTextNode("南京"))
         selectObj.appendChild(myOption)
         selectObj.appendChild(myOption1)
        }
        function choice()
        {
         var index=$("area").selectedIndex;
         var val=$("area").options[index].getAttribute("value")
         if(val==10)
         {
          var i=$("context").childNodes.length-1;
         var remobj=$("context").childNodes[i];
         remobj.removeNode(true)
          var sh=document.createElement_x("select")
          sh.add(new Option("浦东新区","101"))
          sh.add(new Option("黄浦区","102"))
          sh.add(new Option("徐汇区","103"))
          sh.add(new Option("普陀区","104"))
          $("context").appendChild(sh)
         }
         if(val==100)
         {
          var i=$("context").childNodes.length-1;
         var remobj=$("context").childNodes[i];
         remobj.removeNode(true)
          var nj=document.createElement_x("select")
          nj.add(new Option("玄武区","201"))
          nj.add(new Option("白下区","202"))
          nj.add(new Option("下关区","203"))
          nj.add(new Option("栖霞区","204"))
          $("context").appendChild(nj)
         }
        }
        function calc()
        {
         var x=$("context").childNodes.length-1;
         alert(x)
        }
        function remove()
        {
         var i=$("context").childNodes.length-1;
         var remobj=$("context").childNodes[i];
         remobj.removeNode(true)
        }
       </script>
    <body>
    <div id="context">
       <select id="area" onchange="choice()">
       </select>
    </div>
    <input type=button value="显示" onclick="show()">
    <input type=button value="计算结点" onclick="calc()">
    <input type=button value="删除" onclick="remove()">
    </body>
    </html>

    改进版:在select中添加、修改、删除option元素

    function watch_ini(){ // 初始
    for(var i=0; i<arguments.length; i++){
    var word = document.createElement_x("OPTION");
    word.text = arguments[i];
    watch.keywords.add(word); // watch. is form name
    }
    }
    function watch_add(f){ // 增加
    var word = document.createElement_x("OPTION");
    word.text = f.word.value;
    f.keywords.add(word); 
    }
    但上述 add() 方法只在IE下有效,为兼容FF和Opera,对上述代码进行了一下改进,改动后代码如下: function watch_ini(){ // 初始
    for(var i=0; i<arguments.length; i++){
       var oOption=new Option(arguments[i],arguments[i]);
       document.getElementByIdx_x("MySelect")[i]=oOption;
    }
    }
    function watch_add(f){ // 增加
       var oOption=new Option(f.word.value,f.word.value);
       f.keywords[f.keywords.length]=oOption;
    }


    整个实例的完整代码如下:

    <!doctype html public "-//w3c//dtd html 4.0 transitional//en">
    <html>
    <head>
    <title>javascript select options text value</title>
    <meta name="keywords" content="javascript select options text value add modify delete set">
    <meta name="description" content="javascript select options text value add modify delete set">
    <script language="javascript">
    <!--
    function watch_ini(){ // 初始
    for(var i=0; i<arguments.length; i++){
       var oOption=new Option(arguments[i],arguments[i]);
       document.getElementByIdx_x("MySelect")[i]=oOption;
    }
    }
    function watch_add(f){ // 增加
       var oOption=new Option(f.word.value,f.word.value);
       f.keywords[f.keywords.length]=oOption;
    }
    function watch_sel(f){ // 编辑
    f.word.value = f.keywords[f.keywords.selectedIndex].text;
    }
    function watch_mod(f){ // 修改
    f.keywords[f.keywords.selectedIndex].text = f.word.value;
    }
    function watch_del(f){ // 删除
    f.keywords.remove(f.keywords.selectedIndex);
    }
    function watch_set(f){ // 保存
    var set = "";
    for(var i=0; i<f.keywords.length; i++){
    set += f.keywords[i].text + ";";
    }
    confirm(set);
    }
    //-->
    </script>
    </head>
    <body>
    <form name="watch" method="post" action="">
    <select id="MySelect" name="keywords" size="10" onchange="watch_sel(this.form)"></select><br>
    <script language="javascript">
    <!--
    watch_ini("我","你","妳","他","她","它","尔"); // 初始关键词
    //-->
    </script>
    <input type="text" name="word" /><br />
    <input type="button" value="增加" onclick="watch_add(this.form);" />
    <input type="button" value="修改" onclick="watch_mod(this.form);" />
    <input type="button" value="删除" onclick="watch_del(this.form);" />
    <input type="button" value="保存" onclick="watch_set(this.form);" />
    </form>

    用一个字符串创建一个数组方法:

    <script language="javascript">   
    
    </body>
    </html>
    <script>
    function spli(){
    datastr="2,2,3,5,6,6";      
    var str= new Array();    
       str=datastr.split(",");      
        for (i=0;i<str.length ;i++ )   
         { document.write(str[i]+"<br/>");  }   
    }   
    spli();   
    </script
      1. 今天调试了一段js,在ie上运行良好,在火狐上调试出现错误,查资料发现

        obj.add(new Option("文本","值"));    //这个只能在IE中有效
                 obj.options.add(new Option("text","value")); //这个兼容IE与firefox

        因为这段代码,在网上查资料收藏了这篇文章,实时的温故js

        共勉!!

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  • 原文地址:https://www.cnblogs.com/xiaoliu66007/p/4858979.html
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