JS操作select的步骤以及JS全面学习文档

2012-11-07

JS操作select的方法以及JS全面学习文档删除select中的所有OPTIONdocument.getElementByIdx(select的ID).

JS操作select的方法以及JS全面学习文档
删除select中的所有OPTION

document.getElementByIdx("select的ID").options.length = 0;

为select添加一个option

document.getElementByIdx("select的ID").options.add(new Option(text,value));

移除一个指定的OPTION

document.getElementByIdx("select的ID").remove(i);

1.动态建立select

      function createselect(){

var myselect = document.createelement("select");
          myselect.id = "myselect";
          document.body.appendchild(myselect);
      }

2.添加选项option

     function addoption(){

          //按照id查找对象，
           var obj=document.getelementbyid('myselect');

           //添加一个选项
obj.add(new option("文本","值"));    //这个只能在ie中有用
         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.getelementbyid('myselect');
obj.options.length=0;

     }

4.删除一个选项option

function removeone(){
           var obj=document.getelementbyid('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.getelementbyid('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.getelementbyid('myselect');

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

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

7.点窜选项option

var obj=document.getelementbyid('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.getelementbyid("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 $(id)
    {
     return document.getelementbyid(id)
    }
    function show()
    {
     var selectobj=$("area")
     var myoption=document.createelement("option")
     myoption.setattribute("value","10")
     myoption.appendchild(document.createtextnode("上海"))
     var myoption1=document.createelement("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("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("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="计较结点" onclick="calc()">
<input type=button value="删除" onclick="remove()">
</body>
</html>

改良版：在select中添加、点窜、删除option元素

function watch_ini(){ // 初始
for(var i=0; i<arguments.length; i++){
var word = document.createelement("option");
word.text = arguments[i];
watch.keywords.add(word); // watch. is form name
}
}
function watch_add(f){ // 增添
var word = document.createelement("option");
word.text = f.word.value;
f.keywords.add(word);
}
但上述 add() 方式只在ie下有用，为兼容ff和opera，对上述代码进行了一下改良，改动儿女码如下： function watch_ini(){ // 初始
for(var i=0; i<arguments.length; i++){
   var ooption=new option(arguments[i],arguments[i]);
   document.getelementbyid("myselect")[i]=ooption;
}
}
function watch_add(f){ // 增添
   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">

</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">

</script>
<input type="text" name="word" /><br />
<input type="button" value="增添" onclick="watch_add(this.form);" />
<input type="button" value="点窜" onclick="watch_mod(this.form);" />
<input type="button" value="删除" onclick="watch_del(this.form);" />
<input type="button" value="保留" onclick="watch_set(this.form);" />
</form>

用一个字符串建立一个数组方式:

<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>

详情请见附件 1 楼 wangli1997 2011-10-23   非常好，拿来用了

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JS操作select的步骤以及JS全面学习文档