Can you explain the differences between procedural and object-oriented approaches in programming?

Procedural programming is based on a sequence of procedure or function calls that modify the program's state. The main unit is a function, and data and functions are usually separated.

Object-oriented programming (OOP) combines data and methods that operate on this data into objects. The main principles of OOP are encapsulation, inheritance, and polymorphism.

Differences:

• Structure: In procedural approach, the program is a set of functions; in OOP, it is a set of objects.
• Data: In procedural, data and functions are separate; in OOP, data is encapsulated within objects.
• Reusability: OOP facilitates reusability through inheritance and polymorphism.
• Change support: OOP is better suited for complex systems where modeling real entities and their interactions is important.

Example in Java:

Procedural style:

int sum(int a, int b) {
    return a + b;
}

OOP style:

class Calculator {
    int sum(int a, int b) {
        return a + b;
    }
}

In OOP, methods are associated with objects, which allows for better code structuring and state management.