Mastering C# Fundamentals: Data Types, Classes, Inheritance, Polymorphism

Study Notes

Discovering the Building Blocks of C#: Data Types, Classes, Inheritance, Polymorphism

C#, a modern, general-purpose, object-oriented programming language, forms the foundation of many innovative projects across industries. To understand C# fully, we must dive into fundamental concepts such as data types, classes, inheritance, and polymorphism.

Data Types

In C#, values are assigned specific data types, ensuring accurate storage and manipulation. These types encompass numeric values (integer, float, double), characters (char), booleans (bool), strings (string), arrays, and custom types defined within classes.

Classes

Classes act as blueprints for creating objects, organizing related properties and behaviors together. They enable encapsulation through member visibility modifiers, allowing controlled data access. For instance, the following snippet defines a Person class:

public class Person {
    public string Name;
    public int Age;
}

Inheritance

By utilizing inheritance, child classes (subclasses) can extend parent classes (superclasses), inheriting their attributes and behavior. This mechanism promotes logical groupings and simplifies maintenance.

For example, let's introduce two classes—Employee and Manager. While employees share similarities with managers, managers possess unique characteristics:

public abstract class Employee {
    public string Name;
    public int Experience;
    
    public void PrintDetails() {
        Console.WriteLine($"Name: {this.Name}, Experience: {this.Experience}");
    }
}

public class Manager : Employee {
    public decimal Salary;
    
    public override void PrintDetails() {
        base.PrintDetails(); // invoke Employee's PrintDetails()
        Console.WriteLine($", Salary: {this.Salary}");
    }
}

Polymorphism

Polymorphism refers to the ability to treat derived classes through their interfaces, facilitating flexible and expandable designs. This principle fosters code reuse, adaptability, and readability. For example:

void ProcessEmployees(IEnumerable<Employee> employeeCollection) {
    foreach (var emp in employeeCollection) {
        emp.PrintDetails(); // compile-time binding relies upon declared employee type
        Console.WriteLine("-------------------");
    }
}

// Using the function
ProcessEmployees(new List<Employee>() {
    new Employee(),
    new Manager()
});

These pillars form integral components of effective C# development, underpinning robust, scalable, and maintainable applications.

Description

Delve into key concepts of C# programming including data types, classes, inheritance, and polymorphism. Explore how data types ensure accurate storage, classes serve as blueprints for objects, inheritance promotes reusability, and polymorphism enhances flexibility in code design.