CS C#

C#: Methods & Classes

What you will learn

How to define methods and classes, the anatomy of a method signature, and the use of static.

Class and method structure

public class Greeter {
    public static string Greet(string name) {
        return $"Hello, {name}!";
    }

    public static void Main(string[] args) {
        Console.WriteLine(Greet("Alice"));
    }
}

Method anatomy

  • access modifier: public, private, internal, protected
  • static: belongs to the class, not an instance
  • return type: void means no return value
  • method name: PascalCase by convention
  • parameters: typed, in parentheses
  • body: in { }

Properties (C# special feature)

Properties are like smart fields with get/set accessors:

public class Person {
    public string Name { get; set; }  // auto-property
    public int Age { get; private set; }  // read-only externally
    public DateTime CreatedAt { get; } = DateTime.Now;  // getter only
}

String interpolation with $

string name = "Alice";
int age = 25;
Console.WriteLine($"{name} is {age} years old.");

Common mistakes

  • Forgetting that Main must be static — the CLR calls it before any object is created
  • Using string.Format instead of $"" — interpolation is cleaner and faster
  • Confusing public and private — members are private by default in C#
  • Naming methods in camelCase — C# conventions use PascalCase for methods and properties

Quick check below!

Next: LINQ & Collections