js 操作select和option

1、获取选中select的value和text,html代码如下：
one two three
$(“#mySelect”).val(); //获取选中记录的value值
$(“#mySelect option:selected”).text(); //获取选中记录的text值


2、运用new Option(“文本”,”值”)方法添加选项option
var obj = document.getElementById(“mySelect”);
obj.add(new Option(“4”,”4”));


3、删除所有选项option
var obj = document.getElementById(“mySelect”);
obj.options.length = 0;


4、删除选中选项option
var obj = document.getElementById(“mySelect”);
var index = obj.selectedIndex;
obj.options.remove(index);

5、修改选中选项option
var obj = document.getElementById(“mySelect”);
var index = obj.selectedIndex;
obj.options[index] = new Option(“three”,3); //更改对应的值
obj.options[index].selected = true; //保持选中状态

6、删除select
var obj = document.getElementById(“mySelect”);
obj.parentNode.removeChild(obj); //移除当前对象


7、select选择的响应事件
$(“#mySelect”).change(function(){
//添加所需要执行的操作代码
})
1.动态创建select
function createSelect(){
var mySelect = document.createElement_x(“select”);
mySelect.id = “mySelect”;
document.body.appendChild(mySelect);
}

2.添加选项option
复制代码
function addOption(){
//根据id查找对象，
var obj=document.getElementByIdx_x(‘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
}
复制代码

3.删除所有选项option
function removeAll(){
var obj=document.getElementByIdx_x(‘mySelect’);
obj.options.length=0;
}

4.删除一个选项option
function removeOne(){
var obj=document.getElementByIdx_x(‘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.getElementByIdx_x(‘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.getElementByIdx_x(‘mySelect’);
var index=obj.selectedIndex; //序号，取当前选中选项的序号
var val = obj.options[index].text;

7.修改选项option
var obj=document.getElementByIdx_x(‘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.getElementByIdx_x(“mySelect”);
mySelect.parentNode.removeChild(mySelect);
}