I have changed to using true/false for the disabled attribute and am
using
for (J=0;J<Next.length;++J){
F["B"+Next[J]].disabled = false;
DoSpecificTask[State](F);
}
which comes up with "Next has no properties" on selecting either 10 or
11 in the last answer. I cannot see how to cope with this?!
Cheers
Geoff
On Apr 19, 3:45 pm, "T.J. Crowder" <[EMAIL PROTECTED]> wrote:
> Hi Geoff,
>
> > I am not at all clear what I am iterating through?! Presumably through
> > Next?
>
> With the code you quoted, yes. Assuming 'Next' is an array with two
> elements, 'J' will be 0 and then 1. So if 'Next' is [7,8] (state 6 in
> your list), then on the first pass J will be 0 and so Next[J] will be
> 7, and then on the second pass J will be 1 and so Next[J] will be 8.
> JavaScript arrays have a lot more to them than that, though, I'd
> strongly recommend a read through the Arrays part of Chapter 3 of
> JavaScript: The Definitive Guide by David Flanagan. [1] In general,
> in fact, that book rewards any time spent reading it with time-savings
> down-the-line.
>
> The best way to undestand what's happening with your code is to watch
> it run in a debugger like Firebug.
>
> On the code: You seem to be setting the "disabled" property on form
> fields to either "" or "disabled". I'm pretty sure it's a boolean
> property, you probably want to be using false (enabled) and true
> (disabled). Or use Prototype's disable() method. [2]
>
> [1]http://www.oreilly.com/catalog/jscript5/
> [2]http://www.prototypejs.org/api/form/element/disable
>
> Hope this helps,
> --
> T.J. Crowder
> tj / crowder software / com
>
> On Apr 19, 1:29 pm, geoffcox <[EMAIL PROTECTED]> wrote:
>
>
>
> > Thanks again...
>
> > The nearest I can get is
>
> > for (J=0;J<Next.length;++J){
> > F["B"+Next[J]].disabled = ""
> > DoSpecificTask[State](F)
> > }
>
> > which gives the first 3 answers but then the last one is
> > undefined ...?
>
> > I am not at all clear what I am iterating through?! Presumably through
> > Next? One value of Next is 1,2 and presumably that means that
>
> > B1 and B2 should be enabled? They are in fact. So why does this not
> > work for the 4th answer, for B10 and B11?
>
> > Any light on this?!
>
> > Cheers
>
> > Geoff
>
> > On Apr 19, 12:20 pm, "T.J. Crowder" <[EMAIL PROTECTED]> wrote:
>
> > > Geoff,
>
> > > > but not sure how this works with the 2 dimensional array...
>
> > > The array you're looping through with for..in isn't two-dimensional,
> > > is it? You're assigning Next to the sub-array (for lack of a better
> > > term) within Arry, which is just one-dimensional (in fact, typically
> > > single-element, although there are four of them that have two
> > > elements).
>
> > > > From the link you give I should use
>
> > > > for (var index = 0; index < myArray.length; ++index)
> > > > { var item = myArray[index];
> > > > F["B"+Next[J]].disabled = "";
> > > > DoSpecificTask[State](F);
>
> > > > }
>
> > > > but not sure how this works with the 2 dimensional array...
>
> > > > I've tried various permuations but ....
>
> > > I'm guessing you weren't quoting actual code you'd tried? That code
> > > uses 'index' rather than 'J' as your index, uses 'myArray' instead of
> > > 'Next', and assigns 'item' but never uses it.
>
> > > Separately, it's worth pointing out that JavaScript doesn't have multi-
> > > dimensional arrays. It has arrays (which are really maps), and the
> > > value of an element can be an array, but that's very different than
> > > multi-dimensional arrays as in C, C++, and such.
>
> > > Hope this helps,
> > > --
> > > T.J. Crowder
> > > tj / crowder software / com
>
> > > On Apr 19, 11:57 am, geoffcox <[EMAIL PROTECTED]> wrote:
>
> > > > Hello,
>
> > > > Thanks for you reply - I'm having problems getting the iteration to
> > > > work. In fact not sure how to iterate in this case...
>
> > > > From the link you give I should use
>
> > > > for (var index = 0; index < myArray.length; ++index)
> > > > { var item = myArray[index];
> > > > F["B"+Next[J]].disabled = "";
> > > > DoSpecificTask[State](F);
>
> > > > }
>
> > > > but not sure how this works with the 2 dimensional array...
>
> > > > I've tried various permuations but ....
>
> > > > Help!
>
> > > > Cheers
>
> > > > Geoff
>
> > > > On Apr 19, 10:53 am, "T.J. Crowder" <[EMAIL PROTECTED]> wrote:
>
> > > > > Geoff,
>
> > > > > My guess is it's the for..in that's doing you in. Check out the docs
> > > > > on Array
> > > > > (http://www.prototypejs.org/api/array) and Enumerable
> > > > > (http://www.prototypejs.org/api/enumerable)
> > > > > for details. For..in does not iterate the elements of an array; it
> > > > > iterates the properties of an object. These seem like the same thing
> > > > > in some JavaScript implementations (but not all), but that stops
> > > > > happening when Prototype adds its syntactic sugar to Array.
>
> > > > > Separately: You are relying quite heavily on semicolon insertion,
> > > > > which can tend to obscure odd bugs. It's best to always explicitly
> > > > > use semicolons, never to rely on JavaScript to guess correctly where
> > > > > they should go. There are good maintainability reasons for this, as
> > > > > well as the pragmatic reason that you pretty much can't use minimisers
> > > > > on your code if you don't put semicolons in.
>
> > > > > Hope this helps,
> > > > > --
> > > > > T.J. Crowder
> > > > > tj / crowder software / com
>
> > > > > On Apr 19, 8:49 am, geoffcox <[EMAIL PROTECTED]> wrote:
>
> > > > > > Hello,
>
> > > > > > Can anyone please see why as soon as add a link to prototype.js I
> > > > > > get
> > > > > > an error message
>
> > > > > > F["B" + Next[J]] has no properties
>
> > > > > > I have tried changing the variable names but still get the error
> > > > > > message.
>
> > > > > > Help! Cheers Geoff
>
> > > > > > var Arry = [
> > > > > > /* State 0 : */ [1,2],
> > > > > > /* State 1 : */ [3],
> > > > > > /* State 2 : */ [3],
> > > > > > /* State 3 : */ [4,5],
> > > > > > /* State 4 : */ [6],
> > > > > > /* State 5 : */ [6],
> > > > > > /* State 6 : */ [7,8],
> > > > > > /* State 7 : */ [9],
> > > > > > /* State 8 : */ [9],
> > > > > > /* State 9 : */ [10,11]]
>
> > > > > > var result =new Array();
> > > > > > var test_num=1;
> > > > > > function A(f) {soundManager.play('mySound'+test_num
> > > > > > ,'../assets/audio-
> > > > > > group1/Track' + (+test_num + 22) + '.mp3'); }
> > > > > > function B(f) { result[test_num] = "same"; test_num++;}
> > > > > > function C(f) { result[test_num] = "different";test_num++; }
>
> > > > > > DoSpecificTask = [A, B, C, A, B, C, A, B, C, A, B, C]
>
> > > > > > function Fn(Arg) {
> > > > > > var F = Arg.form, State, J, Next
> > > > > > State = Arg.value
> > > > > > for (J=0 ; J<12 ; J++) F["B"+J].disabled = "disabled" // clear
> > > > > > all
> > > > > > Next = Arry[State]
> > > > > > for (J in Next) F["B"+Next[J]].disabled = "" // set some
> > > > > > DoSpecificTask[State](F)
>
> > > > > > }- Hide quoted text -
>
> > > > > - Show quoted text -- Hide quoted text -
>
> > > - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
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