The Object Oriented Programming Languages (OOPL). Done by: Tayeb El Alaoui Supervised by: Dr Driss Kettani

Outline Introduction Team presentation Context presentation Subject presentation Simula Smalltalk Modula-3 Self

Outline Eiffel C++ Java Conclusion Importance of Object Oriented. Advantages of Object Oriented. Programmers interest.

Introduction Team presentation. Context presentation. Subject presentation

Team presentation Tayeb El Alaoui ( Junior student ) Amine Mestari ( senior student )

Context presentation To complete the requirements of our Software Engineering II course. To improve my communication skills. To be in accordance with what we are doing now in the course.

Subject presentation Definition of Object Orientedness: (from Rob Coronel in his book Database Systems ). Definition of Object (by Terry Montlick). two dozen major object-oriented programming languages in use today. This presentation only attempts to look at the meaning of ``Object Oriented'' as a property of Programming Languages.

Simula Creators: Developed at the Norvegian Computing Center by Kristen Nygaard and Ole-Johan Dahl. Influences: Algol 60. Features and design Start version: Activity-process based programming language. Last version: ``classes'' and ``objects''.

Simula Support for objects: Protected state, single inheritance for sub-typing and code sharing, partially abstract classes, method overriding, and nested closures. Drawback: No support for the dynamic dispatch.

Smalltalk Creators: Developed by Alan Kay, Dan Ingalls, and Adele Goldberg at Xerox PARC. Influences B220 Tapes, Sketchpad, Simula, and Lisp. Features and design: It is is an untyped, class based language.

Smalltalk Instance methods are kept locally to each object and can refer to both the class variables and the instance variables. All methods are public, while all attributes are private. Single inheritance, abstract classes, method overriding. Inheritance: code sharing, but also specialization of objects.

Modula-3 Creators Designed by Luca Cardelli, Jim Donahue, Mick Jordan, Bill Kalsow, Greg Nelson. Influences Modula-2+ (and from it: Modula-2, Mesa, Cedar). Features and Design It is a class based language in which class names act as type names.

Modula-3 There are no explicit type definitions or declarations. Class definitions are ``partial opaque'‘. Single Inheritance is provided as a means of type specialization Code reuse and Abstract Classes. Generic Modules for source code reuse. Modula-3 is strongly typed, with no automatic conversion, or type inference.

Self Creators David Ungar and Randall Smith. Influences Smalltalk. Features and Design It is a Classless Language, which uses prototype objects, and cloning to construct new objects.

Self There are no Static types, or type declarations required. All operations are implemented as messages. Every object is composed entirely of slots. Each slot of an object can be thought of as a memory address Inheritance, code sharing and dynamic dispatch are all provided via slots, messages, and cloning.

Eiffel Creators: Eiffel was designed by Bertrand Meyer at Interactive Software Engineering. Influences: Simula67. Features and design: It is a Class based language, in which the definition of "Type'' and ''Class'' are identical.

Eiffel Multiple inheritance. Code reuse. It allows the programmer to not only Redefine the implementation of particular features, but also to modify the Client list of inherited features. It provides Assertions in the form of Invariants over objects.

C++ Creators: Bjarne Stroustrup. Influences: C, Simula, and Cpre. Features and design: It is a class based language, designed to allow the programmer very low level control over object structure and access.

C++ Virtual (abstract) functions and virtual classes. Public/private/protected access control over individual member functions and attributes. Friend classes. Multiple inheritance (for code sharing) Method overloading and exceptions.

Java It is a Class based language. Creators: Developed by by James Gosling, Bill Joy, and Guy Steele at Sun Microsystems. Influences: Modula-3, C++, and Lisp. Features and design: Partial abstract classes.

Java Single and multiple inheritance. Close ties with the Internet and Web browsers. Portable language that can run on any web- enabled computer. No pointers. It has garbage collection. Multiple levels of implementation hiding.  Java is the latest pure OOPL.

Conclusion Object-oriented programming offers a new and powerful model for writing computer software. It improves the maintenance, reusability, and modifiability of a software. Major shift in thinking by programmers.