How to get the value of the multi-select box in jquery (a brief analysis of the method)

In front-end development, it is often necessary to obtain the value of a checkbox for processing or to determine whether it is selected. jQuery is a very popular JavaScript library that provides a rich API that allows us to easily obtain the value of a multi-select box. This article will introduce how to use jQuery to get multi-select boxes.

1. The status of the selected multi-select box

Before getting the value of the multi-select box, we need to first understand the status of the multi-select box, that is, checked (checked) or unchecked (unchecked) ). We can use the .prop() method to get or set the selected state of the multi-select box. The following is an example:

<input type="checkbox" id="checkbox1" value="value1" checked>
<label for="checkbox1">选项1</label>

// 获取checkbox1的选中状态
const isChecked = $('#checkbox1').prop('checked');
console.log(isChecked); // 输出true

The output result of the above example is true, indicating that the multi-select box has been selected. If the checked attribute of the multi-select box is changed to unchecked, the output result will be false.

2. Get the value of the multi-select box

When we need to get the value of the multi-select box, we can use the following method:

1. Use the .each() method Traversing multi-select boxes

We can use jQuery's .each() method to traverse all selected multi-select boxes, obtain their value attributes, and then store these values ​​in an array. The following is an example:

<input type="checkbox" id="option1" value="value1" checked>
<label for="option1">选项1</label>

<input type="checkbox" id="option2" value="value2" checked>
<label for="option2">选项2</label>

<input type="checkbox" id="option3" value="value3">
<label for="option3">选项3</label>

// 获取所有选中的多选框的值，并存储到数组中
const selectedOptions = [];
$('input[type=checkbox]:checked').each(function() {
  selectedOptions.push($(this).val());
});
console.log(selectedOptions); // 输出["value1", "value2"]

The above code uses a selector to select all selected multi-select boxes. Use the .each() method to traverse each selected multi-select box and add the value attribute of these multi-select boxes to the array.

2. Use the .serializeArray() method to get the value of the selected multi-select box

In addition to using the .each() method, we can also use jQuery’s .serializeArray() method to get the selected value The value of the checkbox. This method will return an array containing the values ​​of all selected checkboxes. The following is an example:

<input type="checkbox" id="choice-1" name="choice" value="1" checked>
<label for="choice-1">选项1</label>

<input type="checkbox" id="choice-2" name="choice" value="2" checked>
<label for="choice-2">选项2</label>

<input type="checkbox" id="choice-3" name="choice" value="3">
<label for="choice-3">选项3</label>

// 获取选中的多选框的值
const selectedValues = $('input[name="choice"]:checked').serializeArray();
console.log(selectedValues); // 输出[{name: "choice", value: "1"}, {name: "choice", value: "2"}]

The above code uses a selector to select all selected multi-select boxes. Here we use the .name attribute to select the multi-select box and the .serializeArray() method to get the value of the selected multi-select box.

3. Conclusion

Through the above introduction, we can know how to use jQuery to get the value of the multi-select box. Whether you use the .each() method or the .serializeArray() method, you can handle the value of the multi-select box well. But when using it, you need to make a choice based on the actual situation in order to better implement your own business logic.

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