![10
Basic C++ Extension from C
âą 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 */
âą 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
âą 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)
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 âą Focus on â Programming Concepts â Programming Design Techniques âą Donât get lost in â 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 âą Objects are an Abstraction â represent real world entities â Classes are data types that define shared common properties or attributes â Objects are instances of a class âą Objects have State â have a value at a particular time âą Objects have Operations â associated set of operations called methods that describe how to carry out operations âą Objects have Messages â request an object to carry out one of its operations by sending it a message â 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: âą Define a new type Rectangle (a class) â Data âą width, length â Function âą area() âą Create an instance of the class (an object) âą 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 âą Characteristics of OOPL: âEncapsulation âInheritance âPolymorphism âą OOPLs support : â Modular Programming â Ease of Development â Maintainability
- 8. 8 Characteristics of OOPL âą Encapsulation: Combining data structure with actions â Data structure: represents the properties, the state, or characteristics of objects â Actions: permissible behaviors that are controlled through the member functions Data hiding: Process of making certain data inaccessible âą Inheritance: Ability to derive new objects from old ones â permits objects of a more specific class to inherit the properties (data) and behaviors (functions) of a more general/base class â ability to define a hierarchical relationship between objects âą Polymorphism: Ability for different objects to interpret functions differently
- 9. 9 Basic C++ âą Inherit all ANSI C directives âą Inherit all C functions âą You donât have to write OOP programming in C++
- 10. 10 Basic C++ Extension from C âą 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 */ âą 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 âą 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) âą const â In C, #define statement âą Preprocessor - No type checking. âą #define n 5 â In C++, the const specifier âą Compiler - Type checking is applied âą const int n = 5; // declare and initialize âą New data type â Reference data type â&â. int ix; /* ix is "real" variable */ int & rx = ix; /* rx is âaliasâ for ix. Must initialize*/ ix = 1; /* also rx == 1 */ rx = 2; /* also ix == 2 */
- 12. 12 C++ - Advance Extension âą C++ allows function overloading â In C++, functions can use the same names, within the same scope, if each can be distinguished by its name and signature â The signature specifies the number, type, and order of the parameters expressed as a comma separated list of argument types
- 13. 13 C++ âą Is a better C âą Expressive âą Supports Data Abstraction âą Supports OOP âą Supports Generic Programming â Containers âą Stack of char, int, double etc â Generic Algorithms âą sort(), copy(), search() any container Stack/Vector/List
- 14. 14 Take Home Message âą There are many different kinds of programming paradigms, OOP is one among them. âą In OOP, programmers see the execution of the program as a collection of dialoging objects. âą The main characteristics of OOPL include encapsulation, inheritance, and polymorphism.
- 15. Assignment âą Explain the concept and Methodology of Object Oriented Programming in C++