Count elements that the id begins with a certain string [duplicate]

Question

Possible Duplicate:
jQuery Return elements where ID begins with a certain string

Ok, let's say I have the following elements:

<select id="state_id" value="20">test1</select>
<select id="state_id1" value="21">test2</select>
<select id="state_id2" value="22">test3</select>

How can I get the length() of the select tags that the id begins with state_id in this case?

I have tried: $("^#state_id").length(); but no success.

Any hint?

Answer 1

Try this...

$('[id^=state_]').length