What does it mean, when it’s said that reference data types refer to an object?

Here is the technical explanation you can try to convey him:-

Reference data types in programming language such as java programming language, C++ programming language and C# programming language includes object, arrays and Interfaces.

When you create a variable of a reference type and then assigned it an object, that variable doesn’t contain the data of objects directly however instead hold a reference to where the object is stored in memory.

Thus this can allow multiple variable to refer to the same object and change made through one variable affect the state of the object for all references.

Here is a java example given which would demonstrate reference data types referring to an object:-

Public class ReferenceDataTypeExample {

    Public static void main(String[] args) {

        // Creating an object of type Person

        Person person1 = new Person(“John”, 30);

        // Assigning person1 to person2 (both refer to the same object)

        Person person2 = person1;

        // Modifying person1’s age

        Person1.setAge(35);

        // Accessing person2’s age (reflects the change made to person1)

        System.out.println(“Person2’s Age: “ + person2.getAge()); // Output: Person2’s Age: 35

    }

}

Class Person {

    Private String name;

    Private int age;

    Public Person(String name, int age) {

        This.name = name;

        This.age = age;

    }

    Public int getAge() {

        Return age;

    }

    Public void setAge(int age) {

        This.age = age;

    }

}

Here is the Python programming language example given:-

# Define an abstract Shape class

From abc import ABC, abstractmethod

Class Shape(ABC):

    @abstractmethod

    Def calculate_area(self):

        Pass

# Define a Rectangle class that inherits from Shape

Class Rectangle(Shape):

    Def __init__(self, length, width):

        Self.length = length

        Self.width = width

    Def calculate_area(self):

        Return self.length * self.width

# Define a Circle class that inherits from Shape

Class Circle(Shape):

    Def __init__(self, radius):

        Self.radius = radius

    Def calculate_area(self):

        Return 3.14159 * self.radius * self.radius

# Main program

If __name__ == “__main__”:

    # Create objects of Rectangle and Circle

    Rectangle = Rectangle(5, 10)

    Circle = Circle(7)

    # Using reference data types to refer to objects

    Shape1 = rectangle

    Shape2 = circle

    # Calculate and print areas

    Print(f”Area of Rectangle: {shape1.calculate_area()}”)  # Output: Area of Rectangle: 50

    Print(f”Area of Circle: {shape2.calculate_area()}”)     # Output: Area of Circle: 153.93804002589985