Paradigms and languages on OOFP 2025-26

Paradigm

Mon, 01 Jan 0001 00:00:00 +0000

Paradigm #

A programming paradigm is a way to write programs. Paradigms include:

imperative programming,

object-oriented programming,

functional programming,

logical programming,

etc.

Programming languages are often categorized based on the paradigms that they support.

Disclaimer. The boundaries of a paradigm are not always clear, and can be subjective. For this reason, we will (cautiously) borrow descriptions from Wikipedia.

Imperative programming #

Languages #

The most widely used programming languages are imperative.

Compile time vs runtime error

Mon, 01 Jan 0001 00:00:00 +0000

Compile time vs runtime error #

Definition. In (pre)compiled languages (like Java, C/C++, C#, Haskell, Python, Go, Rust, etc.):

A compile time error prevents a program from compiling. It can be thought of as a “syntactic” error.

A runtime error (also called a bug) occurs during the execution of a program. It may depend on the input of the program.

Note. An IDE can identify some compile time errors (and highlight them), without even attempting to compile the program.

Typing

Mon, 01 Jan 0001 00:00:00 +0000

Typing #

A typing system restricts the values that can be used in certain contexts.

Example. In Java, the following instruction is incorrect, because the variable x has type int, whereas the value "Hi" is a string.
int x = "Hi";
This line of code would generate a compile-time error.

Terminology. In this example, int is called a type annotation.

Static vs dynamic typing #

Static typing #

Definition. A programming language is statically typed if type checks are performed at compile time.

Pure function

Mon, 01 Jan 0001 00:00:00 +0000

Pure function #

Functional languages like Haskell favor pure functions, which behave like mathematical functions.

In imperative code, their adoption varies by language and community. For instance, pure functions are not idiomatic in C, but common in languages like Java, JavaScript, Python or Rust.

Side effect #

Definition. A method/function has a side effect if it modifies a resource (variable, object, array, etc.) that is defined outside of its scope.