Class design
Design the skeleton of the helper library class.
Project: Helper library
In this 5-lesson project you will build a reusable helper library. Each lesson adds one piece, and by the final lesson you will have a working module. All helpers live inside one static class Helpers.
You will use what you learned in previous groups: classes, constructors and inheritance. Static classes are called without creating an instance: Helpers.Capitalize("hello"). That is why helper libraries are designed as static classes.
Static class rules
A static class has three key traits: it cannot be instantiated (new Helpers() is a compile error), all its members must be static (fields, methods, properties), and it cannot inherit or be inherited.
These constraints are ideal for helper libraries. You declare Helpers once; everywhere you call Helpers.MethodName. No need to hold an instance, manage memory, or set up dependencies.
Exercise Define the Helpers static class
Declare a static class Helpers (empty body for now). Inside Main print "Ready" with Console.WriteLine.
Show example solution
Define the class with static class Helpers { }. In Main write Console.WriteLine("Ready");
Example solution:
using System;
static class Helpers
{
}
class Program
{
static void Main()
{
Console.WriteLine("Ready");
}
}Test yourself
-
Which is a static class declaration?
- class Helpers { }
- static class Helpers { }
- static Helpers() { }
- Helpers static { }
Show answer
static class Helpers { } — Correct. static class Helpers { } is a static class declaration.
-
Complete the static class
static ____ Helpers { }Show answer
static class Helpers { } -
Match each keyword to its role
- static
- Makes the class static
- class
- Declares a class
- void
- No return value
- public
- Access from anywhere