The following collection methods help generalize code, make collections easier to use, and make your applications easier to maintain:
| Method Name | Purpose |
|---|
| EXISTS(n) | Returns TRUE if the nth element in a collection exists; otherwise returns FALSE. |
| COUNT | Returns the number of elements that a collection currently contains. |
| LIMIT | Checks the Maximum Size of a Collection. |
| FIRST | Checks the Maximum Size of a Collection. |
| LAST | Returns the last (largest) index numbers in a collection that uses integer subscripts. |
| PRIOR(n) | Returns the index number that precedes index n in a collection. |
| NEXT(n) | Returns the index number that succeeds index n. |
| EXTEND | Appends one null element to a collection. |
| EXTEND(n) | Appends n null elements to a collection. |
| EXTEND(n,i) | Appends n copies of the ith element to a collection. |
| TRIM | Removes one element from the end of a collection. |
| TRIM(n) | Removes n elements from the end of a collection. |
| DELETE | Removes all elements from a collection, setting COUNT to 0. |
| DELETE(n) | Removes the nth element from an associative array with a numeric key or a nested table. If the associative array has a string key, the element corresponding to the key value is deleted. If n is null, DELETE(n) does nothing. |
| DELETE(m,n) | Removes all elements in the range m..n from an associative array or nested table. If m is larger than n or if m or n is null, DELETE(m,n) does nothing. |
