JS動態添加option和刪除option

1.動態創建select

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

2.添加選項option 

function addOption(){ 
    //根據id查找對象， 
    var obj=document.getElementById('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.刪除所有選項option 

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

4.刪除一個選項option

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

5.獲得選項option的值 

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

6.獲得選項option的文本 

var obj=document.getElementById('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option

var obj=document.getElementById('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select

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