Search results
Results From The WOW.Com Content Network
In software engineering, coupling is the degree of interdependence between software modules, a measure of how closely connected two routines or modules are, [1] and the strength of the relationships between modules. [2] Coupling is not binary but multi-dimensional. [3] Coupling and cohesion. Coupling is usually contrasted with cohesion.
Cohesion is often contrasted with coupling. High cohesion often correlates with loose coupling, and vice versa. [2] The software metrics of coupling and cohesion were invented by Larry Constantine in the late 1960s as part of Structured Design, based on characteristics of “good” programming practices that reduced maintenance and ...
The model is named after database pioneer Charles Bachman, and mostly used in computer software design. In a relational model, a relation is the cohesion of attributes that are fully and not transitive functional dependent [clarify] of every key in that relation. The coupling between the relations is based on accordant attributes.
Strong coupling does not allow this. This is a UML diagram illustrating an example of loose coupling between a dependent class and a set of concrete classes, which provide the required behavior: For comparison, this diagram illustrates the alternative design with strong coupling between the dependent class and a provider:
They aid in understanding which classes should go into which packages (package cohesion) and how these packages should relate with one another (package coupling). Package principles also includes software package metrics , which help to quantify the dependency structure, giving different and/or more precise insights into the overall structure ...
The indirection pattern supports low coupling and reuses potential between two elements by assigning the responsibility of mediation between them to an intermediate object. An example of this is the introduction of a controller component for mediation between data (model) and its representation (view) in the model-view-controller pattern.
The database schema is the structure of a database described in a formal language supported typically by a relational database management system (RDBMS). The term " schema " refers to the organization of data as a blueprint of how the database is constructed (divided into database tables in the case of relational databases ).
Chidamber and Kemerer [4] proposed a set of programing complexity metrics widely used in measurements and academic articles: weighted methods per class, coupling between object classes, response for a class, number of children, depth of inheritance tree, and lack of cohesion of methods, described below: