RigaDevDays 2017; 15 May 2017; Riga, Latvia; video is here: https://www.youtube.com/watch?v=K_QEOtYVQ7A

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Yegor Bugayenko
What’s Wrong With
Object-Oriented Programming

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takes.org
eolang.org
“Elegant Objects”

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“Java is the most distressing
thing to happen to computing
since MS-DOS.”
—Alan Kay, 1997

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“Object-oriented programming
offers a sustainable way to
write spaghetti code.”
—Paul Graham, 2003

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“OO seems to bring at least as
many problems to the table as
it solves.”
—Jeff Atwood, 2007

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Google Trends, May 2017
“OOP (blue) vs FP (red)”
https://goo.gl/Ezmma8

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“Objects are not data
structures.”
—Robert Martin, 2014
https://goo.gl/qmRFH4

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—page 98
“A class is a collection of
data fields that hold values
and methods that operate
on those values”

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—page 40
“An object is some memory
that holds a value of some
type.”

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“An object consists of some
private memory and a set of
operations.”
—page 6

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Theory Practicevs.

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Getters & Setters
1

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public class Book {
private String title;
public void setTitle(String t) {
this.title = t;
}
public String getTitle() {
return this.title;
}
}

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Static Methods
2

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public class BookUtils {
public static void print(Book b) {
System.out.println(
“The title is: ” + b.getTitle()
);
}
}

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NULL
3

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Book b = library.find(“UML Distilled”);
if (b == null) {
// The book not found
} else {
System.out.println(
“This is the book: ” + b
);
}

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Reflection
4

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Book b = library.find(“UML Distilled”);
if (b instanceof Ebook) {
String pdf = Ebook.class.cast(b).getPDF();
}

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Inheritance
5

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pubic class Manuscript {
protected String title;
public String html() {
return “<h1>” + this.title + “</h1>”;
}
}
pubic class Book extends Manuscript {
protected String title;
public void rename(String t) {
this.title = t;
}
}

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Annotations
6

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Book b = new Book();
String xml = m.marshall(b);
@XmlRoot
class Book {
@XmlElement
private String title;
}

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“I invented the term object-
oriented, and I can tell you I
did not have C++ in mind.”
—Alan Kay, 1997

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The article on the blog: