If you look @ the document for ".is()"
http://docs.jquery.com/Traversing/is#expr
----------------------------------------------------
Checks the current selection against an expression and returns true,
if at least one element of the selection fits the given expression
----------------------------------------------------
It's looking for a jQuery selector, not a value to compare against
is it finds item matching the selector, you get true, otherwise you
get false
and also (if you read the docs), .val():
----------------------------------------------------
Get the content of the value attribute of the first matched element
----------------------------------------------------
So it is not a jQuery object, hence you cannot do jQuery functions on
it....
On Jan 19, 9:57 am, fredriley <fred.ri...@gmail.com> wrote:
> Hi
>
> My first message on this board after some weeks learning, and fighting
> with, jQuery. My main question is: is there any documentation on
> simple comparative operators in jQuery? I'm thinking of =, <, >, <>,
> that sort of thing. I'm aware that these symbols aren't used in
> jquery, so that to test equality, say, you have to use is(), but I
> can't find any documentation on is() or similar. This has come to mind
> because of the following simple code:
>
> // Choosing 'Other' from the organisation type combo box displays the
> 'other type' field
> $("#myorgtype").change(function()
> {
> var temp = $(this).val();
> alert (temp);
> // if (temp == "Other")
> if ($(this).val().is('Other'))
> {
> alert ('other');
> }
> });
>
> used with a simple combo box:
>
> <select name="myorgtype" id="myorgtype">
> <option value="" selected="selected">Please Select</option>
> <option value="Further Education" >Further Education</
> option>
> <option value="Higher Education" >Higher Education</option>
> <option value="Schools" >Schools</option>
> <option value="NHS">NHS</option>
> <option value="Commercial" >Commercial</option>
> <option value="Other" >Other (please specify)</option>
> </select>
>
> Can't get much simpler. However, the comparative operation:
>
> if ($(this).val().is("Other"))
>
> throws the error:
>
> $(this).val().is is not a function
>
> whereas comparing the value of 'temp' is fine. Ok, no big, not a
> problem, I'll just use the var assignment, but I would like a) to know
> why is() isn't working, and b) to find documentation on comparative
> operators. I've also tried $('#myorgtype option:selected"), and the
> explicit element id rather than 'this', but no dice.
>
> Cheers
>
> Fred
>
> PS: Although I'm a trained and long-experienced programmer and web
> developer, I've found the learning curve for jQuery to be steeper than
> that for Javascript, and have definitely spent longer using jQuery for
> simple operations than I'd have done using bare JS. Now that I've
> invested many tens of hours in jQuery I'll stick with it and I'm sure
> that eventually it's pay productivity dividends, but it has been quite
> a headache... :((
