From Xojo Documentation

Class (inherits from RuntimeException)

Occurs when code tries to access an array element that doesn't exist.

ErrorNumber Message Reason fa-lock-32.png
Stack StackFrames


An OutOfBoundsException error occurs when your code uses an array index that is out of range. This occurs, for example, if you forget that arrays are zero-based and you make an error when you try to access the last element.

Sample Code

This example is supposed to display the fonts installed on the user's computer in a ListBox. It generates an OutOfBoundsException because the loop should be from 0 to nFonts-1 rather than from 1 to nFonts. When the loop gets to nFonts, the value of i is out of range and the error occurs.

Var nFonts As Integer
nFonts = FontCount
For i As Integer = 1 To nFonts

If you run this code in a built application, you will see a generic error message when i reaches the value of nFonts:

An exception of class OutOfBoundsException was not handled. The application must shut down.

You can handle the exception by adding the following code:

Var nFonts As Integer
nFonts = FontCount
For i = 1 To nFonts

Exception err
If err IsA OutOfBoundsException Then
MessageBox("The value: " + i.ToString + " is out of range!")
End If

When this code runs in a built application, the user sees a dialog box that gives the value of the out of range number. The application does not quit when the user accepts the dialog box.

See Also

RuntimeException class; Function, Raise, Sub statements; Nil datatype, Exception, Try statements.