[ Non-logical Variables, Arrays, Bags, Shelves and Stores | Reference Manual | Alphabetic Index ]
bag_count(+BagHandle, -Count)
Get the number of entries in a bag
- BagHandle
- A bag
- Count
- A variable or integer
Description
	This returns an integer corresponding to the number of entries
	currently in the bag. A fresh or erased bag has zero entries.
    
Modes and Determinism
Exceptions
- (4) instantiation fault 
- BagHandle is not instantiated
- (5) type error 
- BagHandle is not a bag
- (5) type error 
- List is instantiated but not to an integer
- (40) stale object handle 
- BagHandle refers to an already destroyed bag
Examples
    ?- bag_create(B), bag_count(B, N0), bag_enter(B, one), bag_count(B, N1).
    N0 = 0
    B = 'BAG'(16'0030dc48)
    N1 = 1
    Yes (0.00s cpu)
    
See Also
bag_create / 1, bag_enter / 2, bag_count / 2, bag_erase / 1, bag_abolish / 1, bag_retrieve / 2, bag_dissolve / 2