getLast

GetLast is a function or method name used in programming to retrieve the last element of a sequence, list, or other ordered collection. The concept is widespread across languages and libraries, though the exact name and behavior can vary. In many APIs, getLast returns the final item according to the collection’s iteration order and does not remove it from the structure.

Behavior and edge cases vary by language. If the underlying collection is non-empty, getLast typically returns that last element. If the collection is empty, the result is language-dependent: some implementations throw an exception (for example, certain variants throw when called on an empty collection), while others return a special value such as null or undefined, and some provide safe variants like getLastOrNull or getLastOrDefault.

Performance characteristics depend on the data structure. In arrays, vectors, or deques with direct tail access, retrieving the last element is often O(1). In singly linked lists or other structures without a cached tail, obtaining the last element may require traversing the entire sequence, resulting in O(n) time.

Variants and related concepts include some languages offering a dedicated last or tail function, while others distinguish between retrieving the last element and removing it (for example, getLast versus popLast). Safe variants reduce error-prone behavior by returning a default value or an optional type when the collection is empty.

Examples by language or library illustrate the diversity: Java’s LinkedList offers getLast() to read the last element; C#’s LINQ provides Last() and LastOrDefault(); Lodash provides last(array); Python typically uses negative indexing (arr[-1]) rather than a getLast method.