How can I change the unselected item to selected item from dropdown list without using the iterator function in Jquery?

How can I change the unselected item to selected item fro开发者_JAVA百科m dropdown list without using the iterator function in Jquery?

Two notes before the answer.

1. selected="true" for HTML, selected="selected" for XHTML
2. Multiple selections need to be enabled on the select

Here is the jQuery "not" selector in action.

$("select option:not(:selected)").attr("selected", "true");