[development] jQuery/javascript - i need help/examples

Earnie Boyd earnie at users.sourceforge.net
Fri Sep 4 18:56:44 UTC 2009


Quoting Seth Freach <sfreach at gmail.com>:

> Earnie,
>
> If you have a simple form as follows:
> <form>
> <input type="text" id="alpha" class="check-on-change" />
>  <input type="text" id="beta" class="check-on-change" />
>  <input type="text" id="gamma" />
> </form>
>
> to do a simple auto population of the third field based on the sum  
> of the first two with jquery would look like this:
> <javascript>
> $(document).ready(function() {
>  $('.check-on-change').change(show_sum);
> });
>
> function show_sum() {
>  var a = $('#alpha").val();
>  var b = $('#beta").val();
>  $('#gamma').val(a + b);
> }
> </javascript>
>
> In jQuery, you access DOM elements with "selectors", which are  
> strings that follow the exact same syntax as CSS, but wrapped in  
> "$(...)".  Once you have accessed them like this, you can perform  
> functions on them such as .val() with no params to /get/ the current  
> form field value, or val(x) with a parameter to /set/ the value.
>
> the first bit, "$(document).ready(function(){...});, set's  
> everything up to work after the DOM has been loaded.
>
> see http://docs.jquery.com/Core, and in particular the section on  
> the left of that page titled "API Reference" for lots more info.
>

Thanks, Seth.  You've got me started and I'm thinking I need to also  
add ['#ahah'] to my forms.  I'm still confused by the various API but  
I'll muddle through it now.

--
Earnie
-- http://r-feed.com/           -- http://for-my-kids.com/
-- http://www.4offer.biz/       -- http://give-me-an-offer.com/




More information about the development mailing list