Karl Jones: Created page with "The '''Law of Demeter''' ('''LoD''') or '''principle of least knowledge''' is a design guideline for developing software, particularly Object-orient..."

2016-04-28T14:24:29Z

Created page with "The '''Law of Demeter''' ('''LoD''') or '''principle of least knowledge''' is a design guideline for developing software, particularly Object-orient..."

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The '''Law of Demeter''' ('''LoD''') or '''principle of least knowledge''' is a design guideline for [[Software development|developing software]], particularly [[Object-oriented programming|object-oriented programs]].

See also [[Separation of concerns]].

== Description ==

In its general form, the LoD is a specific case of [[loose coupling]].

The guideline was proposed at Northeastern University towards the end of 1987, and can be succinctly summarized in each of the following ways:

* Each unit should have only limited knowledge about other units: only units "closely" related to the current unit.
* Each unit should only talk to its friends; don't talk to strangers.
* Only talk to your immediate friends.

The fundamental notion is that a given object should assume as little as possible about the structure or properties of anything else (including its subcomponents), in accordance with the principle of "information hiding".

== Name ==

It is named for its origin in the [[Demeter Project]], an [[adaptive programming]] and [[aspect-oriented programming]] effort.

The project was named in honor of [[Demeter]], “distribution-mother” and the Greek goddess of agriculture, to signify a bottom-up philosophy of programming which is also embodied in the law itself.

== See also ==

* [[Computer science]]
* [[Information hiding]]
* [[Object-oriented programming]]
* [[Principle of least astonishment]]
* [[Separation of concerns]]
* [[Single responsibility principle]]

== External links ==

* [https://en.wikipedia.org/wiki/Law_of_Demeter Law of Demeter]

[[Category:Computer science]]
[[Category:Separation of concerns]]
[[Category:Software engineering]]

Law of Demeter - Revision history

Karl Jones: Created page with "The '''Law of Demeter''' ('''LoD''') or '''principle of least knowledge''' is a design guideline for developing software, particularly Object-orient..."