Programming ParadigmsBhavin Kamani

Cuisine

Music Genre

Imperative Programming

Instructional

Command

Variable State

Conditions

Loops

Direct

Efficient

Inflexible

Side Effects

Assembly, C

COBOL, Visual Basic

Object OrientedProgramming

Abstraction

Maintainibility

Learning Curve

Over Engineering

C++, Java, C#

Ruby, Python

Declarative Programming

"What" instead of "How"

Reduced Side effects

Order of statements not crucial

Domain Specific Languages

SQL

Domain Specific Languages

Regular Expression

Functional Programming

Composability

Concurrency

Learning Curve

Main stream support

LISP, Haskell, Erlang

Closure, Scala, F#

Multi-Paradigm Programming

http://www.99-bottles-of-beer.net

JavaScript

Lyrics99 bottles of beer on the wall, 99 bottles of beer.Take one down and pass it around, 98 bottles of beer on the wall.

98 bottles of beer on the wall, 98 bottles of beer.Take one down and pass it around, 97 bottles of beer on the wall.

97 bottles of beer on the wall, 97 bottles of beer.Take one down and pass it around, 96 bottles of beer on the wall.----------------------------------------------------------------------------------------------------------------------------------------------------

1 bottle of beer on the wall, 1 bottle of beer.Take one down and pass it around, no more bottles of beer on the wall.

No more bottles of beer on the wall, no more bottles of beer. Go to the store and buy some more, 99 bottles of beer on the wall.

Imperative Style

var lyrics = [];

for (var bottles = 99; bottles > 0; bottles--) { lyrics.push(bottles + " bottles of beer on the wall, " + bottles + " bottles of beer"); var next_bottles = ((bottles-1) == 0 ? "no more" : (bottles-1)); lyrics.push("Take one down and pass it around, " + next_bottles + " bottles of beer on the wall."); } var zero_bottle = "No more"; lyrics.push(zero_bottle + " bottles of beer on the wall, " + zero_bottle + " bottles of beer"); lyrics.push("Go to the store and buy some more, " + "99 bottles of beer on the wall.");

document.writeln(lyrics.join("<BR>"));

Object-Oriented Style var BottleSong = function(num_bottles, stanza){ this.num_bottles = num_bottles; this.stanza = stanza; }; BottleSong.prototype = { sing: function(separator){ var beer_form = " bottles of beer"; for (var bottles = this.num_bottles; bottles > 0; bottles--) { this.stanza.addLine(bottles + beer_form + " on the wall, " + bottles + beer_form); var next_bottles = ((bottles-1) == 0 ? "no more" : (bottles-1)); this.stanza.addLine("Take one down and pass it around, " + next_bottles + beer_form + " on the wall."); } var zero_bottle = "No more"; this.stanza.addLine(zero_bottle + beer_form + " on the wall, " + zero_bottle + beer_form); this.stanza.addLine("Go to the store and buy some more, " + this.num_bottles + beer_form + " on the wall."); return this.stanza.write(separator); } }

var Stanza = function(){ this.lines = []; }; Stanza.prototype = { addLine: function(line){ this.lines.push(line); },

write: function(separator) { return this.lines.join(separator); } }

var song = new BottleSong(99, new Stanza()); document.writeln(song.sing("<BR>"));

Functional Style var BottleSong = function(num_bottles){ var bottles = function(n){ return (n == 0 ? "no more" : n) + " bottles"; }

this.num_bottles = num_bottles; this.last_stanza = function(){ return ["No more bottles of beer on the wall, no more bottles of beer.", "Go to the store and buy some more, 99 bottles of beer on the wall."]; } this.stanza = function(n) { var line = [bottles(n) + " of beer on the wall, " + bottles(n) + " of beer."]; line.push("Take one down and pass it around, " + bottles(n-1) + " of beer on the wall."); return line; } }

BottleSong.prototype = { sing: function(separator){ var bottles = _.range(this.num_bottles,0,-1) var that = this; return _.reduce(bottles, function(lyrics, n) { return lyrics.concat(that.verse_n(n)); },[]).concat(that.verse_0()).join(separator); } }

var song = new BottleSong(99); document.writeln(song.sing("<BR>"));

bottles 0 = "no more bottles"bottles 1 = "1 bottle"bottles n = show n ++ " bottles"

verse 0 = "No more bottles of beer on the wall, no more bottles of beer.\n" ++ "Go to the store and buy some more, 99 bottles of beer on the wall."

verse n = bottles n ++ " of beer on the wall, " ++ bottles n ++ " of beer.\n" ++ "Take one down and pass it around, " ++ bottles (n-1) ++ " of beer on the wall.\n"

main = mapM (putStrLn . verse) [99,98..0]

Haskel Solution

(defn bottles-str [n] (str (cond (= 0 n) "no more bottles" (= 1 n) "1 bottle" :else (format "%d bottles" n)) " of beer"))

(defn print-bottle [n] (println (format "%s on the wall, %s." (bottles-str n) (bottles-str n))) (println "Take one down and pass it around," (bottles-str (dec n)) "on the wall.")) (defn sing [n] (dorun (map print-bottle (reverse (range 1 (inc n))))) (println "No more bottles of beer on the wall, no more bottles of beer.") (println "Go to the store and buy some more," (bottles-str n) "on the wall.")) (sing 99)

Clojure Solution

Piet Solution

Whitespace Solution

Paradigm Evolution

Java 8

Lambda Expression