![10
Basic C++ Extension from C
• comments
/* You can still use the old comment style, */
/* but you must be // very careful about mixing them */
// It's best to use this style for 1 line or partial lines
/* And use this style when your comment
consists of multiple lines */
• cin and cout (and #include <iostream.h>)
cout << "hey";
char name[10];
cin >> name;
cout << "Hey " << name << ", nice name." << endl;
cout << endl; // print a blank line
• declaring variables almost anywhere
// declare a variable when you need it
for (int k = 1; k < 5; k++){
cout << k;
}](https://image.slidesharecdn.com/objectorientedprogramming2elementsofprogramming-200514065925/85/Object-oriented-programming-2-elements-of-programming-10-320.jpg)
More Related Content
What's hot (15)
Similar to Object oriented programming 2 elements of programming (20)
More from Vaibhav Khanna (20)
Recently uploaded (20)
Object oriented programming 2 elements of programming
- 1. Object Oriented Programming: 2 Elements of Programming Prof Neeraj Bhargava Vaibhav Khanna Department of Computer Science School of Engineering and Systems Sciences Maharshi Dayanand Saraswati University Ajmer
- 2. Focus of Object oriented Technology • Focus on – Programming Concepts – Programming Design Techniques • Don’t get lost in – Language Technical Details
- 3. What is programming? Programming is taking A problem Find the area of a rectangle A set of data length width A set of functions area = length * width Then, Applying functions to data to solve the problem
- 4. Objects • Objects are an Abstraction – represent real world entities – Classes are data types that define shared common properties or attributes – Objects are instances of a class • Objects have State – have a value at a particular time • Objects have Operations – associated set of operations called methods that describe how to carry out operations • Objects have Messages – request an object to carry out one of its operations by sending it a message – messages are the means by which we exchange data between objects
- 5. 5 OO Perspective Let's look at the Rectangle through object oriented eyes: • Define a new type Rectangle (a class) – Data • width, length – Function • area() • Create an instance of the class (an object) • Request the object for its area In C++, rather than writing a procedure, we define a class that encapsulates the knowledge necessary to answer the question - here, what is the area of the rectangle.
- 6. 6 class Rectangle { private: int width, length; public: Rectangle(int w, int l) { width = w; length = l; } main() { Rectangle rect(3, 5); cout << rect.area()<<endl; } int area() { return width*length; } }; Example Object Oriented Code
- 7. 7 Object-Oriented Programming Languages • Characteristics of OOPL: –Encapsulation –Inheritance –Polymorphism • OOPLs support : – Modular Programming – Ease of Development – Maintainability
- 8. 8 Characteristics of OOPL • Encapsulation: Combining data structure with actions – Data structure: represents the properties, the state, or characteristics of objects – Actions: permissible behaviors that are controlled through the member functions Data hiding: Process of making certain data inaccessible • Inheritance: Ability to derive new objects from old ones – permits objects of a more specific class to inherit the properties (data) and behaviors (functions) of a more general/base class – ability to define a hierarchical relationship between objects • Polymorphism: Ability for different objects to interpret functions differently
- 9. 9 Basic C++ • Inherit all ANSI C directives • Inherit all C functions • You don’t have to write OOP programming in C++
- 10. 10 Basic C++ Extension from C • comments /* You can still use the old comment style, */ /* but you must be // very careful about mixing them */ // It's best to use this style for 1 line or partial lines /* And use this style when your comment consists of multiple lines */ • cin and cout (and #include <iostream.h>) cout << "hey"; char name[10]; cin >> name; cout << "Hey " << name << ", nice name." << endl; cout << endl; // print a blank line • declaring variables almost anywhere // declare a variable when you need it for (int k = 1; k < 5; k++){ cout << k; }
- 11. 11 Basic C++ Extension from C (II) • const – In C, #define statement • Preprocessor - No type checking. • #define n 5 – In C++, the const specifier • Compiler - Type checking is applied • const int n = 5; // declare and initialize • New data type – Reference data type “&”. int ix; /* ix is "real" variable */ int & rx = ix; /* rx is “alias” for ix. Must initialize*/ ix = 1; /* also rx == 1 */ rx = 2; /* also ix == 2 */
- 12. 12 C++ - Advance Extension • C++ allows function overloading – In C++, functions can use the same names, within the same scope, if each can be distinguished by its name and signature – The signature specifies the number, type, and order of the parameters expressed as a comma separated list of argument types
- 13. 13 C++ • Is a better C • Expressive • Supports Data Abstraction • Supports OOP • Supports Generic Programming – Containers • Stack of char, int, double etc – Generic Algorithms • sort(), copy(), search() any container Stack/Vector/List
- 14. 14 Take Home Message • There are many different kinds of programming paradigms, OOP is one among them. • In OOP, programmers see the execution of the program as a collection of dialoging objects. • The main characteristics of OOPL include encapsulation, inheritance, and polymorphism.
- 15. Assignment • Explain the concept and Methodology of Object Oriented Programming in C++