Programming Paradigms

Computer Science: OCR A Level, topic 2.4.3

There are several different types of programming paradigms to help us solve different types of problems.

A programming paradigm is a way of coding to solve a problem.
We have 4 types of paradigm and each one is geared towards certain types of situations.
Within each paradigm there are many different programming languages that all offer different things to each other.
Some programming languages can be used for more than one paradigm.

Procedural programming is the most common paradigm of programming language.
Procedural languages have built in simple data types like string, char, boolean, int and real.
Procedural languages focus on a set of instructions that are followed through to achieve a desired outcome at the end.
Python is foremost a procedural language.

Object orientated programming came about as developers needed to model real world items that could be copied over and over again but given different attributes.
An object “class” is set up and shows the attributes (such as colour of a car) and its behaviours (such as engine_start), this class is a blueprint for creating an object.
Once a class is defined, it can be reused to create “instances” of the object as many times as the developer needs.
Java and Python are object orientated languages.

Declarative languages use statements to describe a problem to be solved instead of how to solve the problem.
The statements are given to the programming language engine, it then figures out how to solve the problem and return a result.
SQL is a declarative language.

In functional programming, functions (not procedures) are the blocks we build programs out of.
Functions are different to procedures as they have to follow set rules:
They must take in valid inputs, return an output, and not have any side effects.
Haskell and Python are examples of languages that can be functional languages.

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