Editing Programming paradigm (section)

=== Declarative languages ===

A [[declarative programming]] program describes what the problem is, not how to solve it. The program is structured as a set of properties to find in the expected result, not as a procedure to follow. Given a database or a set of rules, the computer tries to find a solution matching all the desired properties. An archetype of a declarative language is the [[fourth-generation programming language|fourth generation language]] [[SQL]], and the family of functional languages and logic programming.

[[Functional programming]] is a subset of declarative programming. Programs written using this paradigm use [[subroutine|functions]], blocks of code intended to behave like [[function (mathematics)|mathematical functions]]. Functional languages discourage changes in the value of variables through [[assignment (computer science)|assignment]], making a great deal of use of [[recursion (computer science)|recursion]] instead.

The [[logic programming]] paradigm views computation as [[automated reasoning]] over a body of knowledge. Facts about the [[domain (software engineering)|problem domain]] are expressed as logic formulas, and programs are executed by applying [[inference rule]]s over them until an answer to the problem is found, or the set of formulas is proved inconsistent.