Collection Methods
A variety of methods exist for collections, but not all are relevant for every collection type.
EXISTS(n) – Returns TRUE if the specified element exists.
COUNT – Returns the number of elements in the collection.
LIMIT – Returns the maximum number of elements for a VARRAY, or NULL for nested tables.
FIRST – Returns the index of the first element in the collection.
LAST – Returns the index of the last element in the collection.
PRIOR(n) – Returns the index of the element prior to the specified element.
NEXT(n) – Returns the index of the next element after the specified element.
EXTEND – Appends a single null element to the collection.
EXTEND(n) – Appends n null elements to the collection.
EXTEND(n1,n2) – Appends n1 copies of the n2th element to the collection.
TRIM – Removes a single element from the end of the collection.
TRIM(n) – Removes n elements from the end of the collection.
DELETE – Removess all elements from the collection.
DELETE(n) – Removes element n from the collection.
DELETE(n1,n2) – Removes all elements from n1 to n2 from the collection.