Func delegate type in C Sharp (C#) - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Func delegate example?

Consider the following C# code using a Func delegate. What will be printed to the console?

C Sharp (C#)

Func<int, int, int> multiply = (x, y) => x * y;
Console.WriteLine(multiply(3, 4));

A 12

B Error at compile time

C 34

D 7

💡 Hint

Func delegates can take parameters and return a value. Here it multiplies two integers.

The Func delegate takes two integers and returns their product. multiply(3,4) returns 12.

❓ Predict Output

intermediate

What is the output of this Func with no parameters?

Look at this C# code using a Func delegate with no parameters. What will it print?

C Sharp (C#)

Func<string> greet = () => "Hello World!";
Console.WriteLine(greet());

A Error: Func must have parameters

B greet

C Hello World!

D null

💡 Hint

Func can have zero parameters and return a value.

The Func delegate here takes no parameters and returns the string "Hello World!". Calling greet() prints that string.

🔧 Debug

advanced

What error does this Func delegate code produce?

Examine this C# code snippet. What error will it cause when compiled?

C Sharp (C#)

Func<int, int> square = x => x * x;
int result = square();

A Output: 1

B Runtime error: NullReferenceException

C Output: 0

D Compile-time error: No overload for 'square' takes 0 arguments

💡 Hint

Check how many arguments the Func delegate expects.

The Func delegate expects one integer argument. Calling square() with no arguments causes a compile-time error.

🧠 Conceptual

advanced

How many parameters can a Func delegate have at most?

In C#, what is the maximum number of input parameters a Func delegate can have?

A 16

B 8

C 4

D No limit

💡 Hint

Check the official Microsoft documentation for Func delegates.

Func delegates can have up to 16 input parameters, with the last type parameter being the return type.

❓ Predict Output

expert

What is the output of this nested Func delegate example?

Analyze this C# code using nested Func delegates. What will be printed?

C Sharp (C#)

Func<int, Func<int, int>> add = x => y => x + y;
var addFive = add(5);
Console.WriteLine(addFive(10));

A 510

B 15

C 5

D Compile-time error

💡 Hint

The outer Func returns another Func that adds two numbers.

The outer Func takes x and returns a Func that takes y and returns x + y. add(5) returns a Func adding 5 to its input. addFive(10) returns 15.