The Class and the Object In C++, tackling real-world problems is a critical component. Because C++ is an object-oriented programming language, the program has been developed with C++ objects and classes.
C++ Object:
Before start discussing Object and Class In C++ first, we discuss Object.
An Object is a real-world entity in C++, such as a chair, automobile, pen, phone, laptop, and so on.
To put it another way, an object is an entity with a state and behaviour. Here, state information or data, and behaviour refers to functioning.
The object is a runtime entity, it is created at runtime.
We represent an object as an instance of a class. Objects can be used to access all members of the class.
Let’s look at an example of creating a student class object with s1 as the instance variable.
Student s1; //creating an object of Student In this example, Student is the type and s1 is the reference variable that refers to the instance of Student class.
C++ Class:
In C++, a class is a group of similar objects. It is a template from which objects are created. It can have fields, methods, constructors etc.
Let’s see an example of a C++ class that has three fields only.
class Student
{
public:
int id; //field or data member
float salary; //field or data member
String name;//field or data member
} C++ Object and Class Example:
Let’s see an example of a class that has two fields: id and name. It creates an instance of the class, initializes the object and prints the object value.
#include <iostream>
using namespace std;
class Student {
public:
int id;//data member (also instance variable)
string name;//data member(also instance variable)
};
int main() {
Student s1; //creating an object of Student
s1.id = 324;
s1.name = "Lingaraj Senapati";
cout<<s1.id<<endl;
cout<<s1.name<<endl;
return 0;
}Output:
324
Lingaraj SenapatiC++ Class Example: Initialize and Display data through method:
Let’s see another example of a C++ class where we are initializing and displaying objects through the method.
#include <iostream>
using namespace std;
class Student {
public:
int id;//data member (also instance variable)
string name;//data member(also instance variable)
void insert(int i, string n)
{
id = i;
name = n;
}
void display()
{
cout<<id<<" "<<name<<endl;
}
};
int main(void) {
Student s1; //creating an object of Student
Student s2; //creating an object of Student
s1.insert(203, "Lingaraj");
s2.insert(204, "Senapati");
s1.display();
s2.display();
return 0;
} Output:
203 Lingaraj
204 SenapatiC++ Class Example: Store and Display Employee Information:
Let’s see another example of a C++ class where we are storing and displaying employee information using the method.
#include <iostream>
using namespace std;
class Employee {
public:
int id;//data member (also instance variable)
string name;//data member(also instance variable)
float salary;
void insert(int i, string n, float s)
{
id = i;
name = n;
salary = s;
}
void display()
{
cout<<id<<" "<<name<<" "<<salary<<endl;
}
};
int main(void) {
Employee e1; //creating an object of Employee
Employee e2; //creating an object of Employee
e1.insert(204, "Lingaraj",1000000);
e2.insert(205, "Senapati", 300000);
e1.display();
e2.display();
return 0;
} Output:
204 Lingaraj 1000000
205 Senapati 300000
