js 操作select和option常見用法

1、獲取選中select的value和text,html

<select id="mySelect">
<option value="1">one</option>
<option value="2">two</option>
<option value="3">three</option>
</select>

通過以下script代碼s來獲取選中的value和text

$("#mySelect").val(); //獲取選中記錄的value值
$("#mySelect option:selected").text(); //獲取選中記錄的text值 

2、運用new Option("文本","值")方法添加選項option

var obj = document.getElementById("mySelect");
obj.add(new Option("4","4")); 

3、刪除所有選項option

var obj = document.getElementById("mySelect");
obj.options.length = 0; 

4、刪除選中選項option

var obj = document.getElementById("mySelect");
var index = obj.selectedIndex;
obj.options.remove(index);

5、修改選中選項option

var obj = document.getElementById("mySelect");
var index = obj.selectedIndex;
obj.options[index] = new Option("three",3); //更改對應的值
obj.options[index].selected = true; //保持選中狀態

6、刪除select

var obj = document.getElementById("mySelect");
obj.parentNode.removeChild(obj); //移除當前對象 

7、select選擇的響應事件

$("#mySelect").change(function(){ //添加所需要執行的操作代碼}) 

1.動態創建select

function createSelect(){
var mySelect = document.createElement_x("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.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.刪除所有選項option

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

4.刪除一個選項option

function removeOne(){
var obj=document.getElementByIdx_x('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.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.獲得選項option的文本

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option

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select

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