Adds an element to the collection. Returns TRUE if the element was added successfully. Otherwise returns FALSE.

For a List<T>, the element is added to the end of the list.

For a SortedSet<T>, the element is added to the set according to the comparer implementation (default or custom).

Return type: LOGICAL

Access: PUBLIC

Applies to: Progress.Collections.List<T> class, Progress.Collections.SortedSet<T> class

Syntax

Add (element AS T)
element
The object to add to the collection.

Examples

For a code example showing Add() for a list, see Progress.Collections.List<T> class.

For an code example showing Add() for a sorted set, see Progress.Collections.SortedSet<T> class.

Notes

  • Any iterators on the collection become invalid once Add(), AddAll(), Clear(), Insert(), Remove(), RemoveAt(), or Set() are called, and you must get a new iterator to iterate over the collection.
  • For a SortedSet<T>, Add() raises an error if:
    • the element does not implement Progress.Collections.IComparable<T> interface, if using the default comparer implementation.
    • the element is not a valid object reference (including the unknown value), if using the default comparer.
    • the comparer object specified via the specific constructor has become invalid.
    • the comparer raises an error.
  • Once an element is added to a sorted set, you must call Remove() (to remove the element from the set) before you explicitly delete the object instance while still in use in the set; otherwise errors occur.
  • When an object-oriented ABL object is added to a collection, the reference count of the object is incremented so that it is not garbage collected while it remains in the collection.

See also

<T> Generic type reference