November 22, 2019
Amitraj
Class:-
-> Language supports different data type like int, float, char, long, structure etc. Similar to that C++ supports class data type.
-> A class is a user defined data type which has data members and member functions. They can be accessed through class variables (objects).
-> A class is like a Blue print for an object.
-> By default, All members in the class are Private.
For Ex:
Fruit is a class.
Then mango, orange will be objects of class.
// C++ program using class to calculate Area.
-> Language supports different data type like int, float, char, long, structure etc. Similar to that C++ supports class data type.
-> A class is a user defined data type which has data members and member functions. They can be accessed through class variables (objects).
-> A class is like a Blue print for an object.
-> By default, All members in the class are Private.
For Ex:
Fruit is a class.
Then mango, orange will be objects of class.
Objects
-> Class type variable is known as object.
-> An object is an instance of a class.
-> Objects are basic runtime entities in an object oriented system.
-> In Structured programming problem is divided into function unlike this, in OOPs the problem is divided into objects.
// C++ program using class to calculate Area.
#include<iostream>
using namespace std;
class shape
{
private:
int l,b,area;
public:
void input()
{
cout<<"Enter l and b values:";
cin>>l>>b;
}
void calculate()
{
area = l*b;
}
void output()
{
cout<<"Area is:"<<area;
}
};
int main()
{
shape s;
s.input();
s.calculate();
s.output();
return 0;
}
OUTPUT:
Enter l and b values:6 5
Area is:30
*Abstraction using classes: An abstraction can be achieved using classes. A class is used to group all the data members and member functions into a single unit by using the access specifiers. A class has the responsibility to determine which data member is to be visible outside and which is not.
