Set Value of Input Using Javascript Function

Question

I'm currently using a YUI gadget. I also do have a Javascript function to validate the output that comes from the div that YUI draws for me:

Event.on("addGadgetUrl", "click", function(){
    var url = Dom.get("gadget_url").value;  /* line x ------>*/
    if (url == "") {
        error.innerHTML = "<p> error" /></p>";
    } else {
        /* line y ---> */ 
        /*  I need to add some code in here to set the value of "gadget_url" by "" */
    }
}, null, true);

Here is my div:

<div>
<p>URL</p>
<input type="text" name="gadget_url" id="gadget_url" style="width: 350px;" class="input"/>
<input type="button" id="addGadgetUrl" value="add gadget"/>
<br>
<span id="error"></span>
</div>

As you can see my question is, how can I set the value of gadget_url to be ""?

Solution 1

Try... for YUI

Dom.get("gadget_url").set("value","");

with normal Javascript

document.getElementById('gadget_url').value = '';

with JQuery

$("#gadget_url").val("");

Solution 2

document.getElementById('gadget_url').value = '';

Solution 3

The following works in MVC5:

document.getElementById('theID').value = 'new value';

Solution 4

Depending on the usecase it makes a difference whether you use javascript (element.value = x) or jQuery $(element).val(x);

When x is undefined jQuery results in an empty String whereas javascript results in "undefined" as a String.

Solution 5

document.getElementById('gadget_url').value = 'your value';

View more solutions

Comments

[Sangeet Menon]

Try...Dom.get("gadget_url").set("value","");...I'm not quite sure though

[qbantek]

javascript != MVC5

[Matthew Nichols]

And yet he gave the correct answer. There are newbies that will find this question based on this answer.

[Pogrindis]

Just for brevity and future reference, all id's on the page should ALWAYS be unique

[Kamil Kiełczewski]

@Alastair I confirm - that is not using YUI. However OP in title write "Set Value of Input Using Javascript Function" (not YUI function) so answer meet question requirements

[Timo]

goodForm.coolinput.value='foo', is not possible, why cant I use it instead of addressing the input directly by id`? Wait, here..