In C++, classes are the building blocks of object-oriented programming (OOP). They serve as blueprints or templates for creating objects. Classes define the structure and behavior of objects, encapsulating data (attributes) and functions (methods) that operate on that data.

Here's how you define and use classes in C++:

1. Theclass keyword is used to declare a class.

2. Inside the class, you can define private and public sections. Private members are accessible only within the class, while public members are accessible from outside the class.

3. Data members (attributes) hold the state of objects. They can be of various data types.
4. Member functions (methods) define the behavior of objects. They can have parameters and return values.

• 5. Objects are created by specifying the class name followed by a variable name.
• 6. Class members (both attributes and methods) can be accessed using the dot (.) operator on object instances.

Classes in C++ are fundamental to the object-oriented paradigm and provide a powerful way to organize and structure your code by encapsulating data and behavior into reusable and maintainable units.

#include<iostream.h>
#include<conio.h>
class student
{
char a[10];
int age;
int rollno;
public:
void getdata()
{
cout<<"Enter the Name";
cin>>a;
cout<<"Enter the age";
cin>>age;
cout<<"enter the rollno";
cin>>rollno;
}
void putdata()
{
cout<<"The name is\n"<<a<<endl;
cout<<"The age is\n"<<age<<endl;
cout<<"The roll no is\n"<<rollno<<endl;
}
};
void main()
{
student s;
s.getdata();
s.putdata();
getch();
}