duck typing


duck typing

(programming)A term coined by Dave Thomas for a kind ofdynamic typing typical of some programming languages, suchas Smalltalk, Ruby or Visual FoxPro, where avariable's run-time value determines the operations thatcan be performed on it.

The term comes from the "duck test": if it walks like a duckand quacks like a duck, it must be a duck.

Duck typing considers the methods to which a value respondsand the attributes it posesses rather than its relationshipto a type hierarchy. This encourages greater polymorphismbecause types are enforced as late as possible.

http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/100511.

duck typing

In programming, assigning a type to a variable based on its contents. In other words, if it "walks like a duck and talks like a duck, etc." See typing.