API Reference > bentleyjs-core > Ids Ids Classes for working with unique identifiers. Classes Name Description MutableCompressedId64Set A mutable set of valid Id64Strings sorted in ascending order by the 64-bit unsigned integer value of the Ids. OrderedId64Array A SortedArray of unique Id64Strings sorted in ascending order by the 64-bit unsigned integer values of the Ids. TransientIdSequence Generates unique Id64String values in sequence, which are guaranteed not to conflict with Ids associated with persistent elements or models. Namespaces Name Description CompressedId64Set A compact string representation of an Id64Set. Guid The Guid namespace provides facilities for working with GUID strings using the "8-4-4-4-12" pattern. Id64 The Id64 namespace provides facilities for working with 64-bit identifiers. OrderedId64Iterable A collection of valid Id64Strings sorted in ascending order by the unsigned 64-bit integer value of the Ids. Type Aliases Name Description CompressedId64Set GuidString A string containing a well-formed string representation of a Guid. Id64Arg Used as an argument to a function that can accept one or more Id64Strings. Id64Array An array of Id64Strings. Id64Set A set of Id64Strings. Id64String A string containing a well-formed string representation of an Id64. OrderedId64Iterable Last Updated: 12 June, 2024