Object-oriented programming: Difference between revisions

Revision as of 05:27, 5 March 2025

Revision as of 22:16, 20 March 2025

Line 74:

Meanwhile, in Norway, [[Simula]] was developed during the years 1961–1967.<ref name=simuladev/> Simula introduced essential object-oriented ideas, such as [[Class (computer programming)|classes]], inheritance, and [[Dynamic binding (computing)|dynamic binding]].<ref name="auto">{{Cite journal|last = Holmevik|first = Jan Rune|title = Compiling Simula: A historical study of technological genesis|journal = [[IEEE Annals of the History of Computing]]|volume = 16|issue = 4|pages = 25–37|date = Winter 1994|url = http://www.idi.ntnu.no/grupper/su/publ/simula/holmevik-simula-ieeeannals94.pdf|doi = 10.1109/85.329756|s2cid = 18148999|access-date = 3 March 2018|archive-date = 30 August 2017|archive-url = https://web.archive.org/web/20170830065454/http://www.idi.ntnu.no/grupper/su/publ/simula/holmevik-simula-ieeeannals94.pdf|url-status = dead}}</ref>

Simula was used mainly by researchers involved with [[physical modelling]], like the movement of ships and their content through cargo ports.<ref name="auto"/> Simula is generally accepted as being the first language with the primary features and framework of an object-oriented language.<ref>{{cite websitejournal |last1=Madsen |first1=Ole Lehrman |title=Kristen Nygaard |journal=A.M. Turing Award Laureates |url=https://amturing.acm.org/award_winners/nygaard_5916220.cfm|access-date=4 February 2025}}</ref>

{{Quote box

Line 201:

Data [[Abstraction (computer science)|abstraction]] is a way of organizing code so that only certain parts of the data are visible to related functions ([[data hiding]]). This helps prevent mistakes and makes the program easier to manage. Because data abstraction works well, many programming styles, like object-oriented programming and functional programming, use it as a key principle. [[Encapsulation (computer programming)|Encapsulation]] is another important idea in programming. It means keeping the internal details of an object hidden from the outside code. This makes it easier to change how an object works on the inside without affecting other parts of the program, such as in [[code refactoring]]. Encapsulation also helps keep related code together ([[Coupling (computer programming)|decoupling]]), making it easier for programmers to understand.

In object-oriented programming, objects act as a barrier between their internal workings and external code. Outside code can only interact with an object by calling specific ''public'' methods or variables. If a class only allows access to its data through methods and not directly, this is called [[information hiding]]. When designing a program, it's often recommended to keep data as hidden as possible. This means using local variables inside functions when possible, then private variables (which only the object can use), and finally public variables (which can be accessed by any part of the program) if necessary. Keeping data hidden helps prevent problems when changing the code later.<ref>{{Cite book |last=McDonough |first=James E. |title=Object-Oriented Design with ABAP: A Practical Approach |date=2017 |publisher=[[Apress]] |year=2017 |isbn=978-1-4842-2837-1 |___location= |chapter=Encapsulation |doi=10.1007/978-1-4842-2838-8 |via=[[O'Reilly Media|O'Reilly]]}}</ref> Some programming languages, like Java, control information hiding by marking variables as <code>private</code> (hidden) or <code>public</code> (accessible).{{sfn|Bloch|2018|loc=Chapter §4 Item15 Minimize the accessibility of classes and members|pp=73-77}} Other languages, like Python, rely on naming conventions, such as starting a private method's name with an underscore. Intermediate levels of access also exist, such as Java's <code>protected</code> keyword, (which allows access from the same class and its subclasses, but not objects of a different class), and the <code>internal</code> keyword in C#, Swift, and Kotlin, which restricts access to files within the same module.<ref>{{Cite web |date=2023-01-05 |title=What is Object Oriented Programming (OOP) In Simple Words? – Software Geek Bytes |url=https://softwaregeekbytes.com/object-oriented-programming-simple-words/ |access-date=2023-01-17 |language=en-US}}</ref>

Abstraction and information hiding are important concepts in programming, especially in object-oriented languages.<ref name="Luca1985">{{Cite journal |last1=Cardelli |first1=Luca |last2=Wegner |first2=Peter |date=1985-12-10 |title=On understanding types, data abstraction, and polymorphism |journal=ACM Computing Surveys |language=en |volume=17 |issue=4 |pages=471–523 |doi=10.1145/6041.6042 |issn=0360-0300|doi-access=free }}</ref> Programs often create many copies of objects, and each one works independently. Supporters of this approach say it makes code easier to reuse and intuitively represents real-world situations.<ref>{{cite book|last=Jacobsen|first=Ivar|title=Object Oriented Software Engineering|year=1992|publisher=Addison-Wesley ACM Press|isbn=978-0-201-54435-0|pages=[https://archive.org/details/objectorientedso00jaco/page/43 43–69]|author2=Magnus Christerson|author3=Patrik Jonsson|author4=Gunnar Overgaard|url=https://archive.org/details/objectorientedso00jaco/page/43}}</ref> However, others argue that object-oriented programming does not enhance readability or modularity.<ref name="badprop"/><ref name="armstrongjoe"/> [[Eric S. Raymond]] has written that object-oriented programming languages tend to encourage thickly layered programs that destroy transparency.<ref name="Eric S. Raymond 2003">{{cite web|url=http://www.catb.org/esr/writings/taoup/html/unix_and_oo.html|title=The Art of Unix Programming: Unix and Object-Oriented Languages|author=Eric S. Raymond|date=2003|access-date=6 August 2014}}</ref> Raymond compares this unfavourably to the approach taken with Unix and the [[C programming language]].<ref name="Eric S. Raymond 2003"/>