For example, I create a Single type array.
Dim test() as single
...
'check if user input the data
If test(0) Is Nothing then
...
End If
...
'check if user input the data
If test(0) Is Nothing then
...
End If
After debugging, the error message pop up saing:
"Is" requires operands that have reference types, but this operand has the value type of 'Single'.
It looks like I can not use "Is Nothing" command in the numerical arrays. I notice that even the array has no input, the length of the array is still 1, and the first value, test(0), is zero by default. How can I do to check if the array is not empty and not the default "0" value I want to make sure the user doesn't forget to input data. Any comment is welcome, and thank you very much for your help.
My OS: Win XP SP2, Visual Basic .Net 2003
[Help] How to check if the array is not "Empty"?
CrCr
Dim test(0) As Single ' 1 position
test(0) = 100.1
Dim test2(10) As Single
For i As Integer = 0 To 10 ' 11 positions!
test2(i) = i * 0.5
Next
To test if the array has been assigned, and not just declared:
If test Is Nothing then Messagebox.Show("eek!")
try it with:
Dim test() As Single ' just declared
Dim test2() As Single = New Single() {} ' declared and assigned to an Empty array
test IS nothing, it has not been assigned. (object reference not set to an instance of an object...)
test2 ISNOT nothing, it is assigned to an empty array. test2.Length is 0