Oracle PL/SQL Programming, 5th Edition

Collection Methods (Built-ins)

PL/SQL offers a number of built-in functions and procedures, known as collection methods, that let you obtain information about and modify the contents of collections. Table 12-3 contains the complete list of these programs.

Table 12-3. Collection methods

Method (function or procedure)	Description
COUNT function	Returns the current number of elements in a collection.
DELETE procedure	Removes one or more elements from the collection. Reduces COUNT if the element is not already removed. With VARRAYs, you can delete only the entire contents of the collection.
EXISTS function	Returns TRUE or FALSE to indicate whether the specified element exists.
EXTEND procedure	Increases the number of elements in a nested table or VARRAY. Increases COUNT.
FIRST, LAST functions	Returns the smallest (FIRST) and largest (LAST) subscript in use.
LIMIT function	Returns the maximum number of elements allowed in a VARRAY.
PRIOR, NEXT functions	Returns the subscript immediately before (PRIOR) or after (NEXT) a specified subscript. You should always use PRIOR and NEXT to traverse a collection, especially if you are working with sparse (or potentially sparse) collections.
TRIM procedure	Removes collection elements from the end of the collection (highest defined subscript).

These programs are referred to as methods because the syntax for using the collection built-ins is different from the normal syntax used to call procedures and functions. Collection methods employ a member method syntax that’s ...