| System Functions |
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| Formats | REF({ADD|DROP|READ}
obj_id)
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| Returns | Current reference count value (0 if the object is deleted). | |||||||||
| Description | The
REF ( ) function is used in Object
Oriented Programming to control access to
an object by incrementing or decrementing the reference
count. The DROP OBJECT directive can
also be used to destroy an object. The system sets the reference count for any newly created object to 1 (one). If you plan to use an object more than once, use REF (ADD obj_id) to increment the reference count. When finished with an object, use REF (DROP obj_id) to decrement the reference count. When the reference count becomes zero, the object is deleted. Only objects whose reference count is 1 can be deleted. Once an object is destroyed, its identifier may be re-assigned to another object. You should no longer use the object identifier in your application, as it may reference a totally different object (if the identifier is re-assigned). All objects are destroyed when the application issues a START directive or if the END directive is entered at command mode. REF (READ obj_id) returns the current reference count value. All calls to REF( ) return the current reference count (or 0, if deleted). |
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| See Also | Object
Oriented Programming DEF CLASS Directive PROPERTY Directive LOAD CLASS Directive DROP CLASS Directive LOCAL Directive FUNCTION Directive LIKE Directive PROGRAM Directive RENAME CLASS Directive STATIC Directive DROP OBJECT Directive NEW( ) Create new Object |
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