Object Oriented programming - Revision history

Eac: Added History from old OOP page.

2024-05-01T19:07:39Z

Added History from old OOP page.

Eac: /* Constructors and Destructors */

2024-05-01T19:05:37Z

Constructors and Destructors

Eac: /* Methods */

2024-05-01T19:01:48Z

Methods

Eac: Adding examples of OOP languages

2024-05-01T18:56:44Z

Adding examples of OOP languages

Eac: Added discussion of methods

2020-01-19T06:56:38Z

Added discussion of methods

Eac at 06:40, January 19, 2020

2020-01-19T06:40:39Z

Eac: Correction

2019-12-23T20:09:56Z

Correction

Eac: Minor changes

2019-12-13T01:47:37Z

Minor changes

Eac: Expanded and clarified

2019-12-12T20:26:32Z

Expanded and clarified

DavidB4-bot: /* top */clean up

2016-06-23T15:06:00Z

top: clean up

← Older revision		Revision as of 19:07, May 1, 2024
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	'''Object Oriented programming '''(OOP) languages are based around the paradigm of objects that interact with each other to produce functionality. There are many [[programming language]]s that are designed around object oriented principles, such as [[Java]]. A class is a definition of an object and contains data and/or functions. Functions within a class are called "methods".		'''Object Oriented programming '''(OOP) languages are based around the paradigm of objects that interact with each other to produce functionality. There are many [[programming language]]s that are designed around object oriented principles, such as [[Java]]. A class is a definition of an object and contains data and/or functions. Functions within a class are called "methods".
		+
		+	==History==
		+	The roots of OOP can be traced back to the 1960s and early 1970s. Early attempts to develop object-oriented languages and methodologies include Simula and Smalltalk. However, it was not until the late 1970s and early 1980s that OOP gained significant recognition with the development of languages like C++ and later, Java. These languages provided a practical framework for implementing object-oriented principles and quickly gained popularity.<ref>https://medium.com/javascript-scene/the-forgotten-history-of-oop-88d71b9b2d9f</ref>

	==Definition==		==Definition==

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 ==Constructors and Destructors==
 A constructor is a class method that is automatically called when an instance of the class is instantiated.  The purpose of the constructor is to set up the new instance.  A destructor is a method that is called when an instance of the class is destroyed.  The purpose of the destructor is to clean up just prior to the instance being deleted.  Typically this includes freeing memory pointed to by instance data.  Some programming languages support special constructors called "copy constructors" which are called when an instance is created as a copy of another instance.
 == Example (Java)==

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 A method is a function that is encapsulated within a class.  Methods have some level of scope and some mechanism for inheritance.
-Different languages support different types of scoping.  Typically, these levels are:
+Different languages support different levels of scoping.  Note that this scoping can apply to either data or methods, or both.  Typically, these levels are:
 <ul>
 <li><b>Private</b>: The method is only visible to methods within the class.</li>

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+}
 </pre>
 [[Category:Programming Languages]]

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 Inheritance is the ability for one class to use the data and methods of an ancestor class (or multiple ancestor classes if multiple inheritance is allowed), rather than having to define those again within a new class.  If class B inherits from class A, then class A is called an ancestor class of B, and class B is called a descendant class of A.
-=== Polymorphism ===
+===Polymorphism===
 Polymorphism allows an object to be used in place of an ancestor object without the code that is using it having to know about the descendant. This means that a complex object can appear to be a simple one. The example below shows that you can have a specific model of car, such as the [[Model T]], which looks like and acts like a normal car.  Polymorphism can be implemented in different ways.  [[Smalltalk]] implemented it via messages.  Most compilers that support OOP implement a virtual method table, which is an array of method pointers as per the CORBA standard.  A descendant class instance can be used in place of any ancestor class instance, but an ancestor class instance cannot be used in place of a descendant class instance.
 ===Encapsulation===
-Encapsulation means that the data used by a class is defined within the class itself, rather than having to resort to global data.
+Encapsulation means that the data used by a class is defined within the class itself, rather than the code having to resort to global data.  Further, functions specific to the class, called "methods" are also defined within the class.
 == Classes and Instances ==
 A class is a definition.  In most languages, a class is a data type.  An instance is an instantiation of a class.  It can be considered in terms of a real-world analog: the designs for a pickup truck are akin to a class.  An actual pickup truck build according to those designs is an instance of that class.  The term "object" is often used to refer to either the class, an instance, or the general concept.  The data within an instance is referred to as "instance data".
 ==Constructors and Destructors==

@@ Line 5: / Line 5: @@
 ===Inheritance===
-Inheritance is the ability for one class to use the data and methods of an ancestor class (or multiple ancestor classes if multiple inheritance is allowed), rather than having to define those again within a new class.  If class B inherits from class A, then class A is called an ancestor class of B, and class B is called a descendant class of A.  A decedent class instance can be used in place of any ancestor class instance, but an ancestor class instance cannot be used in place of a descendant class instance.
+Inheritance is the ability for one class to use the data and methods of an ancestor class (or multiple ancestor classes if multiple inheritance is allowed), rather than having to define those again within a new class.  If class B inherits from class A, then class A is called an ancestor class of B, and class B is called a descendant class of A.
 === Polymorphism ===
-Polymorphism allows an object to be used in place of an ancestor object without the code that is using it having to know about the descendent. This means that a complex object can appear to be a simple one. The example below shows that you can have a specific model of car, such as the [[Model T]], which looks like and acts like a normal car.  Polymorphism can be implemented in different ways.  Smalltalk implemented it via messages.  Most compilers that support OOP implement a virtual method table, which is an array of method pointers as per the CORBA standard.
+Polymorphism allows an object to be used in place of an ancestor object without the code that is using it having to know about the descendant. This means that a complex object can appear to be a simple one. The example below shows that you can have a specific model of car, such as the [[Model T]], which looks like and acts like a normal car.  Polymorphism can be implemented in different ways.  Smalltalk implemented it via messages.  Most compilers that support OOP implement a virtual method table, which is an array of method pointers as per the CORBA standard.  A descendant class instance can be used in place of any ancestor class instance, but an ancestor class instance cannot be used in place of a descendant class instance.
 ===Encapsulation===

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-'''Object Oriented programming '''(OOP) languages are based around the paradigm of objects that interact with each other to produce functionality. There are many [[programming language]]s that are designed around object oriented principles, such as [[Java]].
+'''Object Oriented programming '''(OOP) languages are based around the paradigm of objects that interact with each other to produce functionality. There are many [[programming language]]s that are designed around object oriented principles, such as [[Java]].  A class is a definition of an object and contains data and/or functions.  Functions within a class are called "methods".
-== Objects ==
+==Definition==
-Objects are components of an object oriented language, consisting of properties and methods.
+Object Oriented programming is defined by three things: inheritance, polymorphism, and encapsulation.
-An object is also known as a Type or Class.
+===Inheritance===
-== Polymorphism ==
+=== Polymorphism ===
-Polymorphism allows an object to appear as another object. This means that a complex object can appear to be a simple one. The example below shows that you can have a specific model of car, such as the [[Model T]], which looks like and acts like a normal car.
+Polymorphism allows an object to be used in place of an ancestor object without the code that is using it having to know about the descendent. This means that a complex object can appear to be a simple one. The example below shows that you can have a specific model of car, such as the [[Model T]], which looks like and acts like a normal car.  Polymorphism can be implemented in different ways.  Smalltalk implemented it via messages.  Most compilers that support OOP implement a virtual method table, which is an array of method pointers as per the CORBA standard.
-=== Example (Java)===
+===Encapsulation===
 <pre>
 public class ModelT extends Car {

← Older revision		Revision as of 15:06, June 23, 2016
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−	'''Object Oriented programming '''(OOP) languages are based around the paradigm of objects that interact with each other to produce functionality. There are many [[programming language~~\|programming languages~~]] that are designed around object oriented principles, such as [[Java]].	+	'''Object Oriented programming '''(OOP) languages are based around the paradigm of objects that interact with each other to produce functionality. There are many [[programming language]]s that are designed around object oriented principles, such as [[Java]].

	== Objects ==		== Objects ==