How to get the value of a specified option in a drop-down list using JQuery

JQuery is a popular JavaScript library that helps developers write JavaScript code more easily and efficiently. Among form elements, the drop-down list (select) is a very common element. Developers need to use JQuery to obtain the value of the option selected in the drop-down list.

In this article, we will introduce how to use JQuery to get the value of the selected option in a drop-down list.

1. Get the text of the selected option

In a drop-down list, options may have a value attribute and a text attribute. The value attribute represents the value of each option in the drop-down list, and the text attribute represents the text of each option in the drop-down list. If you need to get the text of the item selected by the user, use the following code:

// 获取选中选项的文本值
var selectedText = $("select option:selected").text();

In the above code, we use the "selector" syntax to select the selected element, and then use option:selected Selector syntax to select the selected option. Finally use the text method to get the text of the selected option.

2. Get the value of the selected option

If you need to get the value of the option selected by the user, you must use the value attribute of the option. The following is the code to get the value of the selected option using JQuery:

// 获取选中选项的值
var selectedValue = $("select").val();

In the above code, we directly use the val method to get the value of the selected option. The "select" selector in the selector points to the dropdown list in the HTML element.

3. Listen to changes in the drop-down list

If you need to change other content on the page based on the options selected by the user, you need to add an event listener to perform the corresponding operations . Here is the code to add an event listener to detect changes in the drop-down list and perform other operations:

// 监听下拉列表变化
$("select").change(function() {
  var selectedValue = $(this).val(); // 获取选择的值
  var selectedText = $(this).children("option:selected").text(); // 获取选择的文本

  // 执行其他操作
  console.log("您选择了：" + selectedText + "，它的值是：" + selectedValue);
});

In the above code, we use the change() method to add an event listener for the drop-down list. Once the user selects a new option, the given function is executed. This in this function points to the element itself, so using this.val() you can get the value of the selected option. Finally we use the console.log method to output the text and value of the selected option.

Summary:

In this article, we introduced how to use JQuery to get the value of the selected option in a drop-down list. First, we use the text() method to get the text of the option selected by the user. Second, we get the value of the option selected by the user by directly calling the val() method. Finally, we demonstrated how to perform additional actions when the user changes options by adding a "change" event listener. Hopefully this article will help you write JavaScript code more easily and efficiently.

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