Javascript操作Select和Option
注意:Option中的O是要大写的，不然语法报错1.动态创建select function createSelect(){ var mySelect = document.createElement("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.getElementById('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.getElementById('mySelect'); obj.options.length=0; }4.删除一个选项optionfunction 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.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.text;7.修改选项optionvar obj=document.getElementById('mySelect');var index=obj.selectedIndex; //序号，取当前选中选项的序号var val = obj.options=new Option("新文本","新值");8.删除select function removeSelect(){ var mySelect = document.getElementById("mySelect"); mySelect.parentNode.removeChild(mySelect); }<!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.getAttribute("value") if(val==10) { var i=$("context").childNodes.length-1; var remobj=$("context").childNodes; 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; 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; remobj.removeNode(true) } </script><body><div id="context"> <select id="area" onchange="choice()"> </select></div><input type=button value="显示" ><input type=button value="计算结点" ><input type=button value="删除" ></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("OPTION");word.text = arguments;watch.keywords.add(word); // watch. is form name}}function watch_add(f){ // 增加var word = document.createElement("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,arguments); document.getElementById("MySelect")=oOption;}}function watch_add(f){ // 增加 var oOption=new Option(f.word.value,f.word.value); f.keywords=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"><!--// Author: i@lxl.cn// Modify: i@cnlei.comfunction watch_ini(){ // 初始for(var i=0; i<arguments.length; i++){ var oOption=new Option(arguments,arguments); document.getElementById("MySelect")=oOption;}}function watch_add(f){ // 增加 var oOption=new Option(f.word.value,f.word.value); f.keywords=oOption;}function watch_sel(f){ // 编辑f.word.value = f.keywords.text;}function watch_mod(f){ // 修改f.keywords.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.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"/><input type="button" value="修改"/><input type="button" value="删除"/><input type="button" value="保存"/></form></body></html>
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