Multiple generic parameters in C Sharp (C#) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does it mean to have multiple generic parameters in C#?

It means a class, method, or interface can use more than one placeholder type, allowing it to work with different types at the same time.

beginner

How do you declare a class with two generic parameters in C#?

You write the class name followed by angle brackets with two type names separated by a comma, like: <T1, T2>.

intermediate

Example: What is the correct syntax for a method with two generic parameters?

public void Swap(ref T1 a, ref T2 b) { /* method body */ }

beginner

Why use multiple generic parameters instead of just one?

Because sometimes you want to work with two or more different types at once, like pairing a key and a value in a dictionary.

intermediate

Can generic parameters have constraints when using multiple generic parameters?

Yes, each generic parameter can have its own constraints to limit what types can be used.

How do you declare a generic class with two type parameters in C#?

A class MyClass<T1, T2> {}

B class MyClass<T1; T2> {}

C class MyClass<T1 T2> {}

D class MyClass<T1 & T2> {}

The correct syntax uses commas to separate multiple generic parameters inside angle brackets.

What is the benefit of using multiple generic parameters?

A To avoid using any types

B To make code slower

C To restrict code to only one type

D To work with multiple different types in one class or method

Multiple generic parameters allow handling different types flexibly in the same code.

Which of these is a valid method signature with two generic parameters?

A void Combine<T1 T2>(T1 a, T2 b)

B void Combine<T1; T2>(T1 a, T2 b)

C void Combine<T1, T2>(T1 a, T2 b)

D void Combine<T1 & T2>(T1 a, T2 b)

Generic parameters must be separated by commas inside angle brackets.

Can each generic parameter have its own constraints?

A No, constraints apply to all parameters together

B Yes, each can have different constraints

C Only one parameter can have constraints

D Constraints are not allowed on generic parameters

Each generic parameter can have its own constraints to specify allowed types.

What does this declaration mean? class Pair {}

A A class that works with two types, T1 and T2

B A class that only works with one type

C A method with two parameters

D An error in syntax

This declares a generic class with two type placeholders, T1 and T2.

Explain how to declare and use a class with multiple generic parameters in C#.

Think about how you write a generic class with one parameter, then add another separated by a comma.

Describe the benefits and use cases of multiple generic parameters.

Consider why a dictionary needs two types: one for key, one for value.