Module 1.2: Programming Paradigms

Prelim Topic

Programming Paradigms

• It is a style, or “way” of programming

• Some languages make it easy to write in some but not others.

Imperative Programming

(Major Programming Paradigms)

• Control flow in _ is explicit: commands show how the computation takes place, step by step. Each step affects the global state of the computation.

• Programming with an explicit sequence of commands that update state.

Structured Programming

(Major Programming Paradigms)

• Is a kind of imperative programming where control flow is defined by nested loops, conditionals, and subroutines, rather than via gotos. Variables are generally local to blocks (have lexical scope)

• Programming with clean, goto-free, nested control structures.

Object Oriented Programming

(Major Programming Paradigms)

• Is based on the sending of messages to objects. Objects respond to messages by performing operations, generally called methods. Messages can have arguments. A society of objects, each with their own local memory and own set of operations has a different feel than the monolithic processor and single shared memory feel of non object oriented languages.

Declarative Programming

(Major Programming Paradigms)

• Control flow in _ programming is implicit: the programmer states only what the result should look like, not how to obtain it.

• No loops, no assignments, etc. Whatever engine that interprets this code is just supposed go get the desired information, and can use whatever approach it wants.

• Programming by specifying the result you want, not how to get it.

Functional Programming

(Major Programming Paradigms)

• In _ programming, control flow is expressed by combining function calls, rather than by assigning values to variables

Logic and Constraint Programming

(Major Programming Paradigms)

• These are two paradigms in which programs are built by setting up relations that specify facts and inference rules, and asking whether or not something is true (i.e. specifying a goal.) Unification and backtracking to find solutions (i.e.. satisfy goals) takes place automatically.