使用jQuery在选择列表上设置selected属性 [英] Setting the selected attribute on a select list using jQuery

问题描述

我有以下HTML:

<select id="dropdown">
    <option>A</option>
    <option>B</option>
    <option>C</option>
</select>

我有字符串"B"，所以我想在其上设置selected属性，这样它将是:

I have the string "B" so I want to set the selected attribute on it so it will be:

<select id="dropdown">
    <option>A</option>
    <option selected="selected">B</option>
    <option>C</option>
</select>

我将如何在jQuery中做到这一点?

How would I do this in jQuery?

推荐答案

如果您不介意稍微修改HTML以包含选项的value属性，则可以大大减少执行此操作所需的代码:

If you don't mind modifying your HTML a little to include the value attribute of the options, you can significantly reduce the code necessary to do this:

<option>B</option>

到

<option value="B">B</option>

当您要执行以下操作时这将很有帮助:

This will be helpful when you want to do something like:

<option value="IL">Illinois</option>

有了这个，下面的jQuery将会做出改变:

With that, the follow jQuery will make the change:

$("select option[value='B']").attr("selected","selected");

如果您决定 not 不包括对value属性的使用，则将需要循环浏览每个选项，并手动检查其值:

If you decide not to include the use of the value attribute, you will be required to cycle through each option, and manually check its value:

$("select option").each(function(){
  if ($(this).text() == "B")
    $(this).attr("selected","selected");
});

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