Javascript 通过文本值从下拉列表中选择一个选项元素
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Selecting an option element from a dropdown by its text value
提问by Wooble
Given an HTML form element like:
给定一个 HTML 表单元素，例如：
<select id='mydropdown'>
<option value='foo'>Spam</option>
<option value='bar'>Eggs</option>
</select>
I know I can select the first option with
我知道我可以选择第一个选项
document.getElementById("mydropdown").value='foo'
However, say I have a variable with the value "Spam"; can I select a dropdown item by its text rather than by its value?
但是，假设我有一个值为“Spam”的变量；我可以通过文本而不是值来选择下拉项吗？
回答by David Waters
var desiredValue = "eggs"
var el = document.getElementById("mydropdown");
for(var i=0; i<el.options.length; i++) {
if ( el.options[i].text == desiredValue ) {
el.selectedIndex = i;
break;
}
}
回答by daniellmb
I'd use the selectedIndex or a loop to select the option by text, the code below doesn't work.
我会使用 selectedIndex 或循环来按文本选择选项，下面的代码不起作用。
document.getElementById("mydropdown").text = 'Eggs';
回答by Vismari
If you want to get an option by its innertext and not by the value you can do this:
如果您想通过其内部文本而不是通过值获得选项，您可以这样做：
function go(){
var dropdown = document.getElementById('mydropdown');
var textSelected = 'Spam';
for(var i=0, max=dropdown.children.length; i<max; i++) {
if(textSelected == dropdown.children[i].innerHTML){
alert(textSelected);
return;
}
}
}
回答by kennebec
Older IE does not handle options of a select as child nodes, but all browsers implement the textproperty of a select's option collection.
较旧的 IE 不会将 select 的选项作为子节点处理，但所有浏览器都实现了 select 选项集合的text属性。
function selectbytext(sel, txt){
if(typeof sel== 'string'){
sel= document.getELementById(sel) || document.getELementsByName(sel)[0];
}
var opts= sel.options;
for(var i= 0, L= opts.length; i<L; i++){
if(opts[i].text== txt){
sel.selectedIndex= i;
break;
}
}
return i;
}
