Generic class declaration in C Sharp (C#) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a generic class in C#?

A generic class is a class that can work with any data type. It uses a placeholder (type parameter) that is replaced with a real type when the class is used.

beginner

How do you declare a generic class named <code>Box</code> with one type parameter <code>T</code>?

You write: <pre>public class Box&lt;T&gt; { }</pre> This means <code>Box</code> can hold any type <code>T</code> you choose later.

beginner

Why use generic classes instead of normal classes?

Generic classes let you write flexible and reusable code. You avoid repeating the same code for different data types and get type safety without casting.

beginner

What does <code>T</code> represent in <code>class Box&lt;T&gt;</code>?

T is a type parameter. It is a placeholder for a real data type that you specify when creating an object of the class.

beginner

How do you create an instance of a generic class Box<T> for type int?

You write:

Box<int> intBox = new Box<int>();

This creates a Box that works with integers.

What symbol is used to declare a generic type parameter in a class?

A <>

B ()

C []

D {}

Generic type parameters are declared inside angle brackets <> after the class name.

Which of these is a correct generic class declaration?

A public class List{T} { }

B public class List(T) { }

C public class List[T] { }

D public class List<T> { }

The correct syntax uses angle brackets <> for generic type parameters.

What does the T in class Box<T> stand for?

A A specific type like int

B A placeholder for any type

C A method name

D A variable name

T is a placeholder that can be replaced by any type when the class is used.

Why are generic classes useful?

A They allow code reuse for different data types

B They make code slower

C They only work with strings

D They remove type safety

Generic classes let you write one class that works with many types, improving reuse and safety.

How do you create an object of a generic class Box<T> for strings?

A Box myBox = new Box();

B Box<T> myBox = new Box<T>();

C Box<string> myBox = new Box<string>();

D Box<string> myBox = Box<string>();

You specify the type in angle brackets when creating the object and use the new keyword.

Explain what a generic class is and why it is useful in C#.

Think about how you can write one class to work with many types.

Describe how to declare and create an instance of a generic class with an example.

Use the example of a class named Box with type T.