Programming paradigms and languages

Programming language features exist to provide building blocks to be combined to express programming ideals. Ideally, a programming language should:

express ideas directly in the code;
express independent ideas independently;
express relationships among ideas directly in the code;
combine ideas freely;
combine ideas only where combinations make sense;
express simple ideas simply.

The programming style of a programming language to provide these building blocks may be categorized into programming paradigms. For example, different paradigms may differentiate:

procedural languages, functional languages, and logical languages;
different levels of data abstraction;
different levels of class hierarchy;
different levels of input datatypes, as in container types and generic programming.

Each of these programming styles has contributed to the synthesis of different programming languages.

A programming language is a set of keywords, symbols, identifiers, and rules by which programmers can communicate instructions to the computer. They follow a set of rules called a syntax.

Keywords are reserved words to form declarations and statements.
Symbols are characters to form operations, assignments, control flow, and delimiters.
Identifiers are words created by programmers to form constants, variable names, structure names, and function names.
Syntax Rules are defined in the Backus-Naur form.

Programming languages get their basis from formal languages. The purpose of defining a solution in terms of its formal language is to generate an algorithm to solve the underlining problem. An algorithm is a sequence of simple instructions that solve a problem.

Generations of programming language
Imperative languages
- Fortran
- COBOL
- Algol
- Basic
- C
- C++
Declarative languages
- Lisp
- ML
- Prolog
Object-oriented programming
Syntax and semantics