Understanding the Basics
So, you’re gearing up for that C# developer interview? Excellent choice! But first, let’s dive into a world of object-oriented programming (OOP), where your coding abilities will be put to the ultimate test. Let’s break down some common interview questions and demystify the process. Remember, it’s about understanding concepts and applying them in real-world scenarios.
Object Creation and Initialization
Before we dive into the deeper stuff, you need to get familiar with the core concept: objects. Think of an object as a blueprint for creating real-world entities. For instance, imagine building a car – it has wheels, engine, doors, etc., all represented by separate objects.
In C#, we denote objects using classes. A class acts like a template, defining the structure and behavior of objects that inherit from it. To create your own class, you use the “class” keyword.
Let’s look at a simple example:
class Car
{ // Define data members within the class
public string Make { get; set; } // Constructor and accessor functions for variables
public string Model { get; set; }
public Car(string make, string model) { Make = make; Model = model; }
This code defines a “Car” class with two data members: `Make` and `Model`. You can then instantiate (create) a `Car` object as follows:
Car mycar = new Car("Toyota", "Camry");
The constructor function is crucial for setting up the initial values for these variables when creating a new `Car` object. Just remember to use the proper syntax!
Encapsulation and Data Hiding
A fundamental concept in OOP called encapsulation refers to protecting data within an object from uncontrolled access. It’s like putting your valuables in a safe – only authorized individuals have the key to access them.
Let’s explore how this works:
public int GetProductPrice { get; set;}
This method illustrates encapsulation, as it hides the internal implementation details of its price calculation. The object controls when and how the price is accessed.
Inheritance
Inheritance allows you to build upon existing classes, saving time and effort in code development! Imagine a child blueprint that inherits features from their parent – this is essentially what inheritance allows you to do.
To understand how it works, take the “Car” class we created earlier. You can create subclasses like “SportsCar” or “ElectricCar”. In these sub-classes, you inherit all of the attributes and methods from the `Car` class, but add unique features and functionalities.
Polymorphism
Polymorphism is a fancy word for “many forms.” It means that different objects can respond to the same method call in different ways.
Think about it like this: you have a box of toys, some cars, and building blocks. You could ask each object to “move” – but based on the type, they will move differently.
Abstract Classes
Abstract classes act as blueprints for more specific subclasses, defining common methods or properties that are required by all derived classes. They serve as a foundation for other classes.
Practice Time!
Okay, you’ve got the basics down – now let’s put everything to the test with some hands-on exercises!
**Example:** Implement a `BankAccount` class that allows you to deposit, withdraw, and check the balance.