[Javascript] While statement array losing data

Thu May 17 08:21:47 CDT 2007

Nick, that was excellent.  I added the Value statement, and it works
perfect.  I will also change the other items that you have noted.

Thank you!
Tim

> On 17 May 2007, at 13:21:51, Tim Lewis wrote:
>
>> This list is great!  I come from a VB background, and learning JS.
>> I have
>> a routine in which I load data through DAO into an array.  My
>> problem is
>> that as soon as the program leaves my While statement, the data in the
>> array disappears.  I have studied and studied my code, but I cannot
>> find a
>> reason.  I am very thankful for any help on this.
>>
>> Tim
>
> Hi Tim,
>
> I think the problem is that you are storing  a _reference_ to the
> field containing the result into the array; what you need is to store
> the _value_. IIRC, VB will automatically use the default property,
> Value in this case, of a COM object (which is what DAO objects are),
> but JScript does not do this. As you have stored a reference to the
> field, it will break when the field it refers to goes away as you
> iterate over the RecordSet.
>
> It's a while since I've done any COM work, but I think what you need
> is to change
>
>          sTransCount = SEARCHRESULT("TransactionCount");
>
> to
>
>          sTransCount = SEARCHRESULT("TransactionCount").Value;
>
> and it should be OK.
>
> Note that setting things to Nothing will cause an error, as JScript
> does not have that keyword. Also, you must have the brackets to
> invoke a function; you can't leave them off as in VB. Again, it's
> been a while, but I think that if you replace
>
> objRecordSet.Close;
> objRecordSet = Nothing;
> objConnection = Nothing;
>
> with
>
> objRecordSet.Close();
> delete objRecordSet;
> delete objConnection;
>
> then it should work.
>
> Finally, you define your results array in the function:
>
> var sLineIn = new Array();
>
> This means it is local to the function, so the results array itself
> will disappear when the function ends. If you need to keep this for
> processing elsewhere, you have two options: you can move that line
> outside of the function, making it a global variable, or you can
> return the array from the function:
>
> function blah() {
>     var results = [ ]; // this is a better way than "new Array()"
>     // do stuff to put things into the "results" array
>     return results;
> }
>
> and then assign the result of the function to another array:
>
> var firstResults = blah();
> doSomethingWith(firstResults);
> var secondResults = blah();
> doSomethingWith(secondResults);
>
> HTH,
>
> Nick.
>
>
>> My code is:
>> <html><head>
>> <script language="JavaScript">
>> <!--
>> function Main() {
>> var sDB="C:\\Temp\\LOGDB.MDB";
>> var objConnection = new ActiveXObject("DAO.DBEngine.36");
>> var objRecordSet = objConnection.workspaces(0).OpenDatabase(sDB);
>> var iResultCount=0;iCount=0;
>> var sLineIn = new Array();
>> var sTransCount="";
>> var SEARCHRESULT;
>> sSearchCommand = "SELECT * FROM HL7_Segments WHERE SegmentLineData
>> LIKE
>> '*MSH*'";
>> SEARCHRESULT = objRecordSet.OpenRecordset(sSearchCommand)
>> SEARCHRESULT.MoveFirst();
>> while (! SEARCHRESULT.EOF) {
>>         sTransCount = SEARCHRESULT("TransactionCount");
>>         sLineIn[iResultCount] = sTransCount;
>>         var msg=confirm("iResultLine for "+iResultCount+" is
>> "+sLineIn[iResultCount]); if (msg==false) {return;};
>>         iResultCount++;
>>         SEARCHRESULT.MoveNext(); }
>> for (var iCount=0;iCount<iResultCount;iCount++) {
>> var msg=confirm("Final iResultLine for "+iCount+" is "+sLineIn
>> [iCount]);
>> if (msg==false) {return;}; }
>> objRecordSet.Close;
>> objRecordSet = Nothing;
>> objConnection = Nothing;
>> }
>> -->
>> </script>
>> </head><body><form>
>> <input type="button" value="Click me!" onclick="Main()">
>> </form></body></html>
>>
>>
>> _______________________________________________
>> Javascript mailing list
>> Javascript at LaTech.edu
>> https://lists.LaTech.edu/mailman/listinfo/javascript
>
> --
> Nick Fitzsimons
> http://www.nickfitz.co.uk/
>
>
>
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