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Figure 6. Duuuhhh not quite what we expect<br />
Figure 7. One way of defining an array<br />
What this code actually shows is the fact that<br />
Arrays in VFP.Net are zero based.<br />
The message, “Index out of Bounds” indicates<br />
that one element could not be found by the compiler.<br />
So we can change the code in two ways.<br />
We either make the dimension of the array bigger<br />
as in:<br />
TLOCAL TestArray(7)<br />
TestArray(1) = „Rainer“<br />
TestArray(2) = „Is“<br />
TestArray(3) = „The“<br />
TestArray(4) = „Boss“<br />
TestArray(5) = „in“<br />
TestArray(6) = „Frankfurt“<br />
Figure 8. Null values in an array<br />
Or we start filling the array at position 0 (zero)<br />
as in:<br />
TLOCAL TestArray(6)<br />
TestArray(0) = „Rainer“<br />
TestArray(1) = „Is“<br />
TestArray(2) = „The“<br />
TestArray(3) = „Boss“<br />
TestArray(4) = „in“<br />
TestArray(5) = „Frankfurt“<br />
Either way works, with the seconds method<br />
you are more in line with the way the compiler<br />
works (zero based arrays)<br />
Handling NULL values<br />
Let’s take a closer look at the first way to handle<br />
array elements. We define an array as having 7 elements<br />
(first sample), and then make a call to the<br />
function in our class, of course we set the debugger<br />
so we can take a look at the elements (Figure 8).<br />
As we can see in the debugger, the first position<br />
in our array is not filled, thus NULL<br />
We can handle NULL values in our code as follows:<br />
IF ALEN( toArgs,1) > 0<br />
FOR lni = 1 to ALEN(toArgs,1)<br />
IF toArgs[lni-1] = NULL<br />
MessageBox( ;<br />
„Yoh man, that is a NULL value“)<br />
ELSE<br />
Page 11 FoxRockX December 2009
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