Defaultfunksjon

Defaultfunksjon is a term used in programming to describe a predefined function that serves as a fallback when no user-supplied function is provided in a given context. The concept relies on treating functions as values, so a function can be passed, stored, and invoked like any other data element.

Its purpose is to provide stable, predictable behavior and reduce boilerplate by avoiding explicit checks for the presence of a function. A defaultfunksjon is usually safe and simple, often implemented as a no-op (a function that does nothing) or as a function that returns a sensible default value. In conservative designs, it is designed to be deterministic and to minimize side effects.

Common usage occurs in APIs that accept callbacks or higher-order functions. If a caller omits the callback, the API may invoke the defaultfunksjon. This pattern is also used with default parameters, where a parameter defaults to a defaultfunksjon value.

Implementation patterns include a dedicated no-op function, a function that yields a default value, or a wrapper that guards against errors. Example in practice: function doSomething(onComplete = defaultFunksjon) { onComplete(); }. In languages with default parameters, the default value is declared in the function signature.

Benefits include reduced null checks and cleaner calls; drawbacks include the potential to mask real problems if the default is used without awareness. Clear documentation helps ensure users understand when the default is applied and what behavior to expect.

See also: no-op function, default parameter, higher-order function, callback.