更改HTML Select元素的选定选项

Question

在我的HTML中，我有一个<select>包含三个<option>元素的元素。我想使用jQuery针对Javascript检查每个选项的值var。如果一个匹配，我想设置该选项的选定属性。我该怎么做？

Answer 1

实际上，这里使用jquery的示例均不正确，因为即使值已更改，它们也会使选择显示第一个条目。选择阿拉斯加并让选择项显示正确的项目的正确方法如下：<select id="state">&nbsp; &nbsp; <option value="AL">Alabama</option>&nbsp; &nbsp; <option value="AK">Alaska</option>&nbsp; &nbsp; <option value="AZ">Arizona</option></select>用jQuery将是：$('#state').val('AK').change();

Answer 2

标记<select id="my_select">&nbsp; &nbsp; <option value="1">First</option>&nbsp; &nbsp; <option value="2">Second</option>&nbsp; &nbsp; <option value="3">Third</option></select>jQuery的var my_value = 2;$('#my_select option').each(function(){&nbsp; &nbsp; var $this = $(this); // cache this jQuery object to avoid overhead&nbsp; &nbsp; if ($this.val() == my_value) { // if this option's value is equal to our value&nbsp; &nbsp; &nbsp; &nbsp; $this.prop('selected', true); // select this option&nbsp; &nbsp; &nbsp; &nbsp; return false; // break the loop, no need to look further&nbsp; &nbsp; }});