Which of the following is NOT counted among the four basic features of object-oriented programming?
- A.Abstraction
- B.Inheritance
- C.Recursion
- D.Polymorphism
Correct answer
Explanation
The correct answer is C, Recursion. Recursion is a general programming technique in which a function calls itself, and it works equally well in procedural languages such as C, so it is not a feature of the object-oriented approach. Options A, B and D are wrong as answers because abstraction, inheritance and polymorphism are three of the four pillars of object-oriented programming, the fourth being encapsulation. Abstraction shows only the essential features and hides the implementation, inheritance lets a new class take the properties of an existing one, and polymorphism lets the same name behave differently in different situations. Some books add data hiding and modularity to the list, but when a paper asks for the basic features, the expected set is encapsulation, abstraction, inheritance and polymorphism.
Read the full article: Object-Oriented Programming: Classes, Objects and Pillars
Practice Questions
View allWhich of the following is regarded as the first object-oriented programming language?
- A.Simula 67
- B.FORTRAN
- C.COBOL
- D.BASIC
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Simula 67, designed by Ole-Johan Dahl and Kristen Nygaard, introduced the ideas of class, object and inheritance and is therefore treated as the first object-oriented language, from which C++ and Java later borrowed.
Read the full explanation →Wrapping up of data and the functions that operate on that data into a single unit is called
- A.Inheritance
- B.Encapsulation
- C.Overloading
- D.Compilation
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Encapsulation means binding the data members and the member functions that act on them inside one unit, the class, and keeping the data private so that it can be reached only through the methods provided; the standard illustration is a capsule holding the medicine inside it.
Read the full explanation →Showing only the essential features of an object to the user while hiding its internal details is known as
- A.Abstraction
- B.Encapsulation
- C.Inheritance
- D.Instantiation
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Abstraction presents only what the user needs, such as the accelerator and brake of a car, and keeps the internal working out of sight; in C++ it is obtained through abstract classes with pure virtual functions and in Java through interfaces and abstract classes.
Read the full explanation →Who developed the C++ programming language?
- A.Dennis Ritchie
- B.James Gosling
- C.Bjarne Stroustrup
- D.Guido van Rossum
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Bjarne Stroustrup developed the language at Bell Laboratories, starting it as C with Classes and giving it the name C++ in 1983; it adds classes, inheritance and polymorphism to C while keeping C procedural power, which is why it is called a hybrid language.
Read the full explanation →The Java programming language was developed at Sun Microsystems under the leadership of
- A.Alan Kay
- B.James Gosling
- C.Anders Hejlsberg
- D.Ken Thompson
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James Gosling and his team at Sun Microsystems developed Java, which was first called Oak and was released under the name Java in 1995; its programs are compiled to bytecode and run on the Java Virtual Machine, which makes them platform independent.
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