js操做select和option

時間 2019-11-11

原文原文鏈接

1.動態建立selectjavascript

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

2.添加選項optionhtml

function addOption(){
          //根據id查找對象，
          var obj=document.getElementByIdx_x('mySelect');
          //添加一個選項
          obj.add(new Option("文本","值"));    //這個只能在IE中有效
          obj.options.add(new Option("text","value")); //這個兼容IE與firefox
}

3.刪除全部選項optionjava

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

4.刪除一個選項option數組

function removeOne(){
            var obj=document.getElementByIdx_x('mySelect');
            //index,要刪除選項的序號，這裏取當前選中選項的序號
            var index=obj.selectedIndex;
            obj.options.remove(index);
}

5.得到選項option的值app

var obj=document.getElementByIdx_x('mySelect');
 
var index=obj.selectedIndex; //序號，取當前選中選項的序號
 
var val = obj.options[index].value;

6.得到選項option的文本post

var obj=document.getElementByIdx_x('mySelect');
 
var index=obj.selectedIndex; //序號，取當前選中選項的序號
 
var val = obj.options[index].text;

7.修改選項optionui

var obj=document.getElementByIdx_x('mySelect');
 
var index=obj.selectedIndex; //序號，取當前選中選項的序號
 
var val = obj.options[index]=new Option("新文本","新值");

8.刪除selectthis

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

整個實例的完整代碼以下：spa

<!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("浦東新區","101"))
       sh.add(new Option("黃浦區","102"))
       sh.add(new Option("徐彙區","103"))
       sh.add(new Option("普陀區","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("玄武區","201"))
       nj.add(new Option("白下區","202"))
       nj.add(new Option("下關區","203"))
       nj.add(new Option("棲霞區","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="顯示" onclick="show()">
 <input type=button value="計算結點" onclick="calc()">
 <input type=button value="刪除" onclick="remove()">
 </body>
 </html>

改進版：在select中添加、修改、刪除option元素firefox

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){ // 增長
     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，爲兼容FF和Opera，對上述代碼進行了一下改進，改動後代碼以下：
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){ // 增長
    var oOption=new Option(f.word.value,f.word.value);
    f.keywords[f.keywords.length]=oOption;
}

整個實例的完整代碼以下：

<!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){ // 增長
    var oOption=new Option(f.word.value,f.word.value);
    f.keywords[f.keywords.length]=oOption;
 }
 function watch_sel(f){ // 編輯
 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){ // 刪除
 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","爾"); // 初始關鍵詞
 //-->
 </script>
 <input type="text" name="word" /><br />
 <input type="button" value="增長" onclick="watch_add(this.form);" />
 <input type="button" value="修改" onclick="watch_mod(this.form);" />
 <input type="button" value="刪除" onclick="watch_del(this.form);" />
 <input type="button" value="保存" onclick="watch_set(this.form);" />
 </form>

用一個字符串建立一個數組方法:

<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 
今天調試了一段js，在ie上運行良好，在火狐上調試出現錯誤，查資料發現
 
obj.add(new Option("文本","值"));    //這個只能在IE中有效
          obj.options.add(new Option("text","value")); //這個兼容IE與firefox

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