containsKeykey

ContainsKeykey is a hypothetical function used in discussions of data access patterns to check for the presence of a key within a map-like collection. The name combines the common containsKey concept with an extra key, and it is not part of a formal standard. In examples, containsKeykey typically operates on dictionary, map, or associative array structures and may support either a single key or a path of keys in a nested structure.

Usage and behavior: For a flat map, containsKeykey(m, k) returns true when m has a top-level entry with key k. For nested structures, variants allow a path such as containsKeykey(m, ['a','b','c']) or containsKeykey(m, 'a.b.c'), returning true only if the entire path exists. Some implementations also treat null values as present keys, depending on design.

Language-specific illustrations: In JavaScript, a simple form is containsKeykey(obj, key) returning Object.prototype.hasOwnProperty.call(obj, key). For nested paths, code can iterate or reduce over the path array. In Java, containsKeykey could be expressed as map.containsKey(key) for a straightforward map, while a nested-path variant might be implemented as a wrapper that traverses intermediate maps. In practice, developers usually rely on standard APIs rather than a nonstandard containsKeykey name.

Notes: The term is primarily used in teaching and documentation examples to illustrate the concept of key existence checks, not as a recommended production API name. When documenting real software, prefer established methods such as containsKey, contains, has, or containsKey depending on language conventions.