Declaring an object variable declares an object reference:
uo_emp_data uo_emp1, uo_emp2 // Two object references
Using the CREATE statement creates an instance of the object:
uo_emp1 = CREATE uo_emp_data
When you assign one object variable to another, a reference to the object instance is copied. Only one copy of the object exists:
uo_emp2 = uo_emp1 // Both point to same object instance
Assignments between ancestor and descendent objects occur in the same way, with an object reference being copied to the target object.
Suppose that uo_emp_data is an ancestor user object of uo_emp_active and uo_emp_inactive.
Declare variables of the ancestor type:
uo_emp_data uo_emp1, uo_emp2
Create an instance of the descendant and store the reference in the ancestor variable:
uo_emp1 = CREATE USING "uo_emp_active"
Assigning uo_emp1 to uo_emp2 makes both variables refer to one object that is an instance of the descendant uo_emp_active:
uo_emp2 = uo_emp1
For information about passing objects as function arguments, see “Passing arguments to functions and events”.
