C# Access Modifiers

C# Access Modifiers

By now, you have probably noticed the public keyword used in our previous examples.

In C#, public is an access modifier. Access modifiers are used to set the visibility level (or access level) for classes, fields, methods, and properties. They control which parts of your code can "see" and interact with other parts.

Types of Access Modifiers

C# offers several access modifiers, but the most common ones you need to know are:

The private Modifier

If you declare a field as private, it cannot be accessed from outside the class. If you try to do so, C# will throw an error.

class Car 
{
  // private by default, but you can explicitly write 'private'
  private string model = "Mustang"; 
}

class Program 
{
  static void Main(string[] args) 
  {
    Car myObj = new Car();
    // ERROR: 'Car.model' is inaccessible due to its protection level
    // Console.WriteLine(myObj.model); 
  }
}

The public Modifier

If you declare a field as public, it can be accessed from anywhere, including from different classes!

using System;

class Car 
{
  public string model = "Mustang"; 
}
class Program 
{
  static void Main(string[] args) 
  {
    Car myObj = new Car();
    // This works perfectly!
    Console.WriteLine(myObj.model); 
  }
}

Why Use Access Modifiers?

You might wonder, "Why not just make everything public?"

The primary reason is Security. By keeping fields private, you prevent outside classes from messing with data they shouldn't touch. This concept is known as Encapsulation, which ensures that sensitive data is hidden from users. We will learn how to safely expose private data using Properties in the next lesson!