Difference Between Functional and Logical Programming

Last Updated : 24 Feb, 2022

Programming paradigm is an approach to solve problems using some programming language or also we can say it is a method to solve a problem using tools and techniques that are available to us following some approach. There are lots of programming languages that are known but all of them need to follow some strategy when they are implemented and this methodology/strategy is paradigms. Apart from varieties of programming languages, there are lots of paradigms to fulfill each and every demand. They are discussed below as follows:

Functional Programming is a type of programming paradigm in which everything is done with the help of functions and using functions as its basic building blocks. In it, we simply try to bind each and everything in a purely mathematical functions' style. Programs are generally written at a higher level and are therefore much easier to comprehend.

Logical Programming is a type of programming paradigm that uses logic circuits to control how facts and rules about the problems within the system are represented or expressed. In it, logic is used to represent knowledge, and inference is used to manipulate it. It tells the model about how to accomplish a goal rather than what goal to accomplish.

Now let us go through the major key differences between them after going through the basics of both of them. Differences are shown below in a tabular format as follows:

Functional Programming	Logical Programming
It is totally based on functions.	It is totally based on formal logic.
In this programming paradigm, programs are constructed by applying and composing functions.	In this programming paradigm, program statements usually express or represent facts and rules related to problems within a system of formal logic.
These are specially designed to manage and handle symbolic computation and list processing applications.	These are specially designed for fault diagnosis, natural language processing, planning, and machine learning.
Its main aim is to reduce side effects that are accomplished by isolating them from the rest of the software code.	Its main aim is to allow machines to reason because it is very useful for representing knowledge.
Some languages used in functional programming include Clojure, Wolfram Language, Erland, OCaml, etc.	Some languages used for logic programming include Absys, Cycl, Alice, ALF (Algebraic logic functional programming language), etc.
It reduces code redundancy, improves modularity, solves complex problems, increases maintainability, etc.	It is data-driven, array-oriented, used to express knowledge, etc.
It usually supports the functional programming paradigm.	It usually supports the logic programming paradigm.
Testing is much easier as compared to logical programming.	Testing is comparatively more difficult as compared to functional programming.
It simply uses functions.	It simply uses predicates. Here, the predicate is not a function i.e., it does not have a return value.