<programming> A term coined by Dave Thomas for a kind of dynamic typing typical of some programming languages, such as Smalltalk, Ruby or Visual FoxPro, where a variable's run-time value determines the operations that can be performed on it.
The term comes from the "duck test": if it walks like a duck and quacks like a duck, it must be a duck.
Duck typing considers the methods to which a value responds and the attributes it posesses rather than its relationship to a type hierarchy. This encourages greater polymorphism because types are enforced as late as possible.
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Nearby terms: dual ported « dual-stack « Dual Tone Multi Frequency « duck typing » DUEL » duff » Duff's device