Purpose
Returns a null pointer value.
Syntax
NULL()
or
NULL
The second syntax form can be used only when the BUILTIN attribute is specified.
Examples
IF LAST_POINTER = NULL() THEN CALL FINISH;
In this example, the IF statement determines whether the pointer variable LAST_POINTER is null; if so, the CALL statement executes.
Description
The NULL function returns a null pointer value. The default NULL value is -1 (all 1 bits). This value is a fictitious address, which is distinct from any valid pointer address.
The -setnull compiler option allows you to designate a particular null pointer value for the NULL function at compile time. For a description of the -setnull compiler option, see your Open PL/I User's Guide.