CODEWITHSUNDEEP
javascriptjqueryhtml-select
B. Clay Shannon-B. Crow Raven
B. Clay Shannon-B. Crow Raven

Reputation: 10297

How to set .selectedIndex with jQuery

I have some html selects:

<select class="form-control, dropdown" id="delperffrom" name="delperffrom">
. . .
<select class="form-control, dropdown" id="delperfto" name="delperfto">
. . .

I want to initialize them to "no value" and so have this javascript, which works:

document.getElementById("delperffrom").selectedIndex = -1;

..and this jQuery, which doesn't:

$("#delperfto").selectedIndex = -1;

Why does the jQuery not work?

Upvotes: 1

Views: 13856

Answers (2)

The Process
The Process

Reputation: 5953

The .selectedindex is property of the DOM element, not jQuery.You can change it on DOM element, or using jQuery .prop() method:

$("#delperffrom")[0].selectedIndex = -1; // change on dom element pulled from jQuery
$("#delperffrom").prop('selectedIndex',-1); // change with .prop() jquery method

Upvotes: 16

jfriend00
jfriend00

Reputation: 708156

Because $("#delperfto") is NOT a DOM element. It's a jQuery object and a jQuery object does not have a .selectedIndex property. A jQuery object is its own type of object with its own properties and methods. It does not have the same properties and methods as a DOM element. It often has a way of accomplishing the same thing, but usually with different syntax.

You can either fetch a DOM element from the jQuery object and access that DOM element directly like this:

$("#delperfto")[0].selectedIndex = -1;

or

$("#delperfto").get(0).selectedIndex = -1;

Or, you can use jQuery's .prop() method to have it set the desired property on each DOM element for you like this:

$("#delperfto").prop("selectedIndex", -1);

There's no particular advantage to one or the other in this specific circumstance, but if your selector returned more than one element in it such as this:

$(".options").prop("selectedIndex", -1);

then the jQuery .prop() method would set that property on all DOM elements that the selector matched, not just the first one which can sometimes be quite useful.

Upvotes: 5

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