Specify the method of assigning values ​​to the drop-down box

This time I will bring you how to assign a value to the drop-down box. What are the precautions for assigning a value to the drop-down box? The following is a practical case, let's take a look.

jsImplementation:

1. Select the i-th option by letting it be selected. The code is as follows: (id is the drop-down box id)

(1) document.getElementById("id").options[i].selected=true;

(2) document.getElementById("messagetoid").selectedIndex = 1; (Select the first option)

2. This is achieved by judging the value of option. The code is as follows:

document.getElementById("messagetoid").value=""; (select the option whose value is empty)

jQueryImplementation:

1. By selecting the i-th option, similar to js implementation 1, the code is as follows:

$("#id").get(0).selectedIndex =

1;(Select the first option)

2. To achieve this by judging the value of option, there are two methods. The code is as follows:

(1) $("#id").val("123"); (Select the option with value "123")

(2) $("#messagetoid").attr("value", ""); (Select the option whose value is empty)

EasyUI implementation:

$('#id').combobox('setValue','A'); (Select the option whose value is A,)

I believe you have mastered it after reading the case in this article For more exciting methods, please pay attention to other related articles on the php Chinese website!

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