Instances in OOP

In object-oriented programming (OOP), instances of a class are also referred to as objects. Objects are created based on a class definition, and each object represents a unique instance of that class.

1. Class Definition:

• A class is a blueprint or template that defines the structure and behavior of objects.
• It encapsulates data (attributes) and functions (methods) that operate on that data.

// Class definition
class MyClass {
public:
    // Member function to set the value of the member variable
    void setValue(int val) {
        myValue = val;
    }

    // Member function to get the value of the member variable
    int getValue() {
        return myValue;
    }

private:
    // Private member variable
    int myValue;
};

2. Creating Instances (Objects):

• Objects are instances of a class. They represent specific entities based on the class blueprint.
• You create an object by declaring a variable of the class type.

// Creating instances (objects) of MyClass
MyClass obj1;  // obj1 is an object of MyClass
MyClass obj2;  // obj2 is another object of MyClass

3. Manipulating Objects:

• Objects have their own set of member variables and can be manipulated using member functions.

// Setting values for obj1 and obj2
obj1.setValue(42);
obj2.setValue(99);

// Retrieving values from obj1 and obj2
int value1 = obj1.getValue();
int value2 = obj2.getValue();

4. Independence of Objects:

• Each object created from the same class is independent of others.
• Changes to one object do not affect the state of other objects.

// obj1 and obj2 have independent states
std::cout << "Value of obj1: " << value1 << std::endl;
std::cout << "Value of obj2: " << value2 << std::endl;