n is either 0, 1, or 2. The default value is 0.
The parameter Undefined specifies the behavior when ObjectScript attempts to fetch the value of a variable that has not been defined. The value of Undefined may be 0, 1, or 2:
0 - Always throw an <UNDEFINED> error. (default)
1 - If the undefined variable has subscripts, return a null string, but if the undefined variable is single-valued, throw an <UNDEFINED> error.
2 - Always return a null string.
Changing This Parameter
On the Compatibility page Management Portal (System Administration > Configuration > Additional Settings > Compatibility), in the Undefined row, click Edit. Select the option you want.
Instead of using the Management Portal, you can change Undefined in the Config.Miscellanous class (as described in the class reference) or by editing the CPF in a text editor (as described in the Editing the Active CPF section of the “Introduction to the Configuration Parameter File” chapter in this book).