How to change DropDownList Selected value in Javascript?

Question

how to change the selected value in javascript and get the selected value in codebehind page? AutoPostBack is set to false.

score 28 · Answer 1 · answered Apr 05 '12 at 13:22

28

You can change it like this:

var ddl = document.getElementById('ddl-id');
var opts = ddl.options.length;
for (var i=0; i<opts; i++){
    if (ddl.options[i].value == "some-value"){
        ddl.options[i].selected = true;
        break;
    }
}

answered Apr 05 '12 at 13:22

Software Engineer

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but when your page gets postback the value will be changed to which was set by the pageload. then what to do??? – King of kings Sep 16 '14 at 10:21

score 15 · Answer 2 · answered Apr 05 '12 at 13:17

15

//setting the value of a drop down list
document.getElementById('my_drop_down').selectedIndex=2;

answered Apr 05 '12 at 13:17

Avi Y

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I am not sure what you mean by 'code behind page'. But this is the way to get the selected value of a dropdown list: document.getElementById('dropdown').value – Avi Y Apr 08 '12 at 07:44
To add to Avi Y's comment, selectedIndex of 2 is the 3rd item in the list, since the index starts at 0. Also, setting the index to -1, clears the dropdown of any text. https://www.w3schools.com/jsref/prop_select_selectedindex.asp#:~:text=Definition%20and%20Usage,of%20the%20first%20option%20selected. – ctay Jun 30 '20 at 14:24

How to change DropDownList Selected value in Javascript?

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