Relation To Other Patterns
It can be regarded as a special case of the State pattern and the Strategy pattern.
It is not a pattern from Design Patterns, but is mentioned in Martin Fowler's Refactoring and Joshua Kerievsky's book on refactoring in the Insert Null Object refactoring.
Chapter 17 is dedicated to the pattern in Robert Cecil Martin's Agile Software Development: Principles, Patterns and Practices
Read more about this topic: Null Object Pattern
Famous quotes containing the words relation to, relation and/or patterns:
“The adolescent does not develop her identity and individuality by moving outside her family. She is not triggered by some magic unconscious dynamic whereby she rejects her family in favour of her peers or of a larger society.... She continues to develop in relation to her parents. Her mother continues to have more influence over her than either her father or her friends.”
—Terri Apter (20th century)
“You know there are no secrets in America. Its quite different in England, where people think of a secret as a shared relation between two people.”
—W.H. (Wystan Hugh)
“One can describe a landscape in many different words and sentences, but one would not normally cut up a picture of a landscape and rearrange it in different patterns in order to describe it in different ways. Because a photograph is not composed of discrete units strung out in a linear row of meaningful pieces, we do not understand it by looking at one element after another in a set sequence. The photograph is understood in one act of seeing; it is perceived in a gestalt.”
—Joshua Meyrowitz, U.S. educator, media critic. The Blurring of Public and Private Behaviors, No Sense of Place: The Impact of Electronic Media on Social Behavior, Oxford University Press (1985)