我真的很喜欢@Marko Dunic 的解决方案，但它不能满足我将 ID 附加到选项的需求。附加 ID 后，我意识到我可以使 JS 代码更小更简单。我的解决方案是为数据来自关系数据库而设计的，JSON 输入数据保留带有主键/外键的关系结构。这是 JSON 数据：
<html lang="en">
<head>
<title>Populate a select dropdown list with jQuery - WebDev Ingredients</title>
<script type="text/javascript" src="js/jquery-1.4.2.js"></script>
<script type="text/javascript">
var types = [
{ typeID: 1, name: 'Domestic'},
{ typeID: 2, name: 'Import'},
{ typeID: 3, name: 'Boat'}
]
var makes = [
{ typeID: 1, makeID: 1, name: 'Chevy'},
{ typeID: 1, makeID: 2, name: 'Ford'},
{ typeID: 1, makeID: 3, name: 'Delorean'},
{ typeID: 2, makeID: 4, name: 'Honda'},
{ typeID: 2, makeID: 5, name: 'Toyota'},
{ typeID: 2, makeID: 6, name: 'Saab'}
]
var model = [
{ makeID: 1, modelID: 1, name: 'Camaro'},
{ makeID: 1, modelID: 2, name: 'Chevelle'},
{ makeID: 1, modelID: 3, name: 'Nova'},
{ makeID: 2, modelID: 4, name: 'Focus'},
{ makeID: 2, modelID: 5, name: 'Galaxie'},
{ makeID: 2, modelID: 6, name: 'Mustang'},
{ makeID: 4, modelID: 7, name: 'Accord'},
{ makeID: 4, modelID: 8, name: 'Civic'},
{ makeID: 4, modelID: 9, name: 'Odyssey'},
{ makeID: 5, modelID: 10, name: 'Camry'},
{ makeID: 5, modelID: 11, name: 'Corolla'}
]
//
// Put this in a stand alone .js file
//
// returns array of elements whose 'prop' property is 'value'
function filterByProperty(arr, prop, value) {
return $.grep(arr, function (item) { return item[prop] == value });
}
// populates select list from array of items given as objects: { name: 'text', value: 'value' }
function populateSelect(el, items) {
el.options.length = 0;
if (items.length > 0)
el.options[0] = new Option('please select', '');
$.each(items, function () {
el.options[el.options.length] = new Option(this.name, this.value);
});
}
// initialization
$(document).ready(function () {
// populating 1st select list
populateSelect($('#sType').get(0), $.map(types, function(type) { return { name: type.name, value: type.typeID} }));
// populating 2nd select list
$('#sType').bind('change', function() {
var theModels = filterByProperty(makes, 'typeID', this.value);
populateSelect($('#sMake').get(0), $.map(theModels, function(make) { return { name: make.name, value: make.makeID} }));
$('#sMake').trigger('change');
});
// populating 3nd select list
$('#sMake').bind('change', function() {
var theSeries = filterByProperty(model, 'makeID', this.value);
populateSelect($('#sModel').get(0), $.map(theSeries, function(model) { return { name: model.name, value: model.modelID} }));
});
});
</script>
</head>
<body>
Enter values, click submit, and look at the post parameters
<form method="get" action="index.php">
<div id="selection">
<select id="sType" name="type_id" style="{width=75px}"></select>
<select id="sMake" name="make_id" style="{width=75px}"></select>
<select id="sModel" name="model_id" style="{width=75px}"></select>
</div>
<input type="submit">
</form>
</body>
</html>
请注意，我的解决方案改变了功能，因此 Make-Model 是第二和第三个文本框，而 Type（domestic、import、boat 等）是第一级。我将样板 JS 减少到 23 行（更少的注释），同时保留了良好的格式。
JSON 数据很容易从 SQL 查询中呈现，因为 Type-Make-Model 很少改变，SQL 查询在初始化时缓存在 java 列表中。我不使用任何动态 AJAX，因为这会使架构复杂化，而且我的可用值列表相对较小，所以我只是在页面请求时发送它。
“解决方案应该尽可能简单，但不能更简单”——A.爱因斯坦