Php Jquery-无法自动选择从回调派生的特定选项

目标：页面加载时默认选择产品三，使用Jquery，而不是硬编码

来自MySQL的数据： HTML

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如果能提供任何解决方案，我们将不胜感激。谢谢。

以下两种变体都适合我：

$('#product-selection option[value="pd3"]').prop("selected", true)
$('#product-selection option[value="pd3"]').prop("selected", "selected")

确保在插入服务器的HTML后运行此代码：

$(document).ready(function() {

    $.post('load.php', {
        req: 'load_product'
    }, function(data, status) {
        $("#product-selection").empty().append(data);

        // Selection code needs to go into this callback,
        // which is executed after the response comes back.
        $('#product-selection option[value="pd3"]').prop("selected", "selected")

    });

    // Selection code SHOULD NOT be here, because this is executed
    // right after the POST request is made.
    // When code at this place is executed, the response has most
    // likely not come back yet.
});

请检查一下。 您可以设置动态值“pdvalue”。当页面加载时，您可以使用它

var pdvalue=pd2； $document.readyfunction{ $.post'load.php'{ 请求：“加载产品” }，功能数据，状态{ $product-selection.empty.APPENDATA； };

---

//$'product-selection'.valpd3；谢谢。对于我的情况，Jquery回调加载在一个模板中，当用户访问HTML页面时，它首先调用模板，然后选择与用户相关的相应产品。因此，我无法将选择代码放入回调模板中，即在functiondata、status之后。

    $(document).ready(function() {
        $.post('load.php', {
            req: 'load_product'
        }, function(data, status) {
            $("#product-selection").empty().append(data);
        });
        // $('#product-selection').val("pd3"); <-Refer to Item 5. Problem
    });

    Callback Return:
    <option selected disabled></option>
    <option value="pd1">Product One</option>
    <option value="pd2">Product Two</option>
    <option value="pd3">Product Three</option>
    <option value="pd4">Product Four</option>

    1. $('#product-selection').val("pd3");
    2. $('#product-selection').val("pd3").change();
    3. $('#product-selection').val("pd3").trigger('change');
    4. $('#product-selection option[value="pd3"]').prop('selected', true);
    5. $('#product-selection option[value="pd3"]').prop('selected', true).change();
    6. $('#product-selection option[value="pd3"]').prop('selected', true).trigger('change');

    Have tried prop / attr, ('selected', true) / ('selected', 'selected') as well. Not working.

$('#product-selection option[value="pd3"]').prop("selected", true)
$('#product-selection option[value="pd3"]').prop("selected", "selected")

$(document).ready(function() {

    $.post('load.php', {
        req: 'load_product'
    }, function(data, status) {
        $("#product-selection").empty().append(data);

        // Selection code needs to go into this callback,
        // which is executed after the response comes back.
        $('#product-selection option[value="pd3"]').prop("selected", "selected")

    });

    // Selection code SHOULD NOT be here, because this is executed
    // right after the POST request is made.
    // When code at this place is executed, the response has most
    // likely not come back yet.
});