PGP Demo Examples

Each paradigm lesson names a small set of representative languages — the ones that make that paradigm's ideas most visible. Every one of those languages gets a short, self-contained example here, syntax-highlighted for that specific language in the code viewer, so you can see the paradigm's shape in real code without installing anything.

How to use: click View to open a file in the code viewer and read its comments. These are teaching snippets, not runnable projects — most need only a standard interpreter/compiler for that language if you want to try them yourself (a Prolog demo needs SWI-Prolog, a Lisp demo needs any Common Lisp, and so on).

Linear

#	Language	Description	Link
1	XML	A data-oriented document, read top to bottom, no branching.	View
2	BASIC	Classic line-numbered BASIC, written without GOTO to show pure linear flow.	View

Structured

#	Language	Description	Link
3	Pascal	Decision, repetition, and selection — the three block shapes, in the language designed to teach them.	View
4	Fortran	The same three shapes in the language that made structured programming famous alongside Algol.	View

Object-Oriented

#	Language	Description	Link
5	Smalltalk	The language that defined OOP's vocabulary — everything is an object, responding to messages.	View
6	Java	Encapsulation, inheritance, and polymorphism, in the language that made OOP mainstream.	View

Functional

#	Language	Description	Link
7	Lisp	The first functional language (1960): functions as data, recursion instead of loops.	View
8	Haskell	Pure functions, immutability, and laziness, taken to their logical conclusion.	View

Logic

#	Language	Description	Link
9	Prolog	Facts and rules instead of steps — you describe relationships, the engine searches for answers.	View

Aspect-Oriented

#	Language	Description	Link
10	AspectJ	A logging aspect that crosscuts every matching method call, without editing those methods.	View

Component-Oriented

#	Language	Description	Link
11	JavaScript (Web Components)	A self-contained, reusable `<counter-button>` element with its own encapsulated state.	View
12	C#	Interchangeable components composed entirely through an interface, never a concrete class.	View

Hybrid

#	Language	Description	Link
13	Python	Structured, object-oriented, and functional style mixed freely in one small file.	View

Practice move: pick one demo whose language you've never touched — Prolog and Smalltalk are the least familiar to most readers — and try to explain, line by line, what makes it feel different from the language you use daily. That difference is the paradigm.