get index of item in listbox

TheInsider · Jan 7, 2003

Hello,
Is there a built-in method [that works in both IE and Netscape] to get the index of an item in a combo/listbox based on its value or text, other than using a for-loop?

In my onSubmit event I validate some user input, based on some criteria I may need to automatically select a certain option in a combo box. I am currently using a for-loop, but I don't want to re-invent the wheel. I know that I could use the following to do the selection:

Code:

combobox.selectedIndex = [desired index]

However, the combo box data is loaded from a table and if records are added or subtracted from the table, the index will change.

Thanks,
TheInsider

jemminger · Jan 7, 2003

no core js method to get selectedIndex by text or value...you'll have to stick with the loop.

=========================================================
if (!succeed) try();
-jeff

TheInsider · Jan 8, 2003

Thanks for the reply. I'm actually trying to set the index by value/text... but in any case, I think you are right. The MSDN help files list the functions selectByValue and selectByText... but javascript doesn't seem to acknowledge these.

Here's Microsoft's example:

Code:

function thisPage_onenter()
{
   ListBox1.addItem(&quot;Cars&quot;, 1);
   ListBox1.addItem(&quot;Planes&quot;, 2);
   ListBox1.addItem(&quot;Trains&quot;, 3);
   ListBox1.selectByValue(1);
}

didn't work for me though...

jemminger · Jan 8, 2003

you can make your own though:
[tt]
<script language="javascript">
function selectByValue(oSel,sVal) {
for (x = 0; x < oSel.options.length; x++)
if (oSel.options[x].value == sVal) {
oSel.options[x].selected = true;
return true;
}
}
</script>

<body onload="selectByValue(document.forms[0].sel,'3');">
<form>
<select name="sel">
<option value="1">one</option>
<option value="2">two</option>
<option value="3">three</option>
</select>
</form>
</body>

[/tt]
=========================================================
if (!succeed) try();
-jeff

TheInsider · Jan 8, 2003

Thanks for the reply. That is the function that I am currently using. I just wanted to know if I was re-writing a function that is already supplied by javascript. Apparently not.
Thanks again,
TheInsider

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get index of item in listbox

TheInsider

Programmer

jemminger

Programmer

TheInsider

Programmer

jemminger

Programmer

TheInsider

Programmer

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