Relational patterns in C Sharp (C#) - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of relational pattern matching with switch

What is the output of this C# code using relational patterns in a switch expression?

C Sharp (C#)

int number = 15;
string result = number switch
{
    < 10 => "Less than 10",
    >= 10 and <= 20 => "Between 10 and 20",
    > 20 => "Greater than 20",
    _ => "Unknown"
};
Console.WriteLine(result);

A Less than 10

B Unknown

C Greater than 20

D Between 10 and 20

💡 Hint

Check which relational pattern matches the value 15.

The value 15 matches the pattern '>= 10 and <= 20', so the output is 'Between 10 and 20'.

❓ Predict Output

intermediate

Result of relational pattern in if statement

What will be printed by this C# code that uses relational patterns in an if statement?

C Sharp (C#)

int age = 65;
if (age is > 60)
{
    Console.WriteLine("Senior");
}
else
{
    Console.WriteLine("Not senior");
}

A Senior

B No output

C Compilation error

D Not senior

💡 Hint

Check if the age is greater than 60.

The age 65 is greater than 60, so the condition is true and 'Senior' is printed.

❓ Predict Output

advanced

Output of nested relational patterns in switch

What is the output of this C# code using nested relational patterns in a switch expression?

C Sharp (C#)

int score = 85;
string grade = score switch
{
    < 60 => "F",
    >= 60 and < 70 => "D",
    >= 70 and < 80 => "C",
    >= 80 and < 90 => "B",
    >= 90 => "A",
    _ => "Invalid"
};
Console.WriteLine(grade);

A C

B A

C B

D D

💡 Hint

Find the range where 85 fits.

85 is between 80 and 90, so the grade is 'B'.

❓ Predict Output

advanced

Value of variable after relational pattern matching

What is the value of the variable 'category' after running this C# code?

C Sharp (C#)

int temperature = 0;
string category = temperature switch
{
    < 0 => "Freezing",
    >= 0 and < 15 => "Cold",
    >= 15 and < 25 => "Warm",
    >= 25 => "Hot",
    _ => "Unknown"
};

A "Cold"

B "Warm"

C "Freezing"

D "Hot"

💡 Hint

Check which pattern matches temperature 0.

0 is >= 0 and < 15, so category is 'Cold'.

❓ Predict Output

expert

Output of complex relational pattern with property

What is the output of this C# code using relational patterns with a property in a switch expression?

C Sharp (C#)

record Product(string Name, decimal Price);

Product item = new("Book", 19.99m);
string priceCategory = item switch
{
    { Price: < 10 } => "Cheap",
    { Price: >= 10 and <= 20 } => "Moderate",
    { Price: > 20 } => "Expensive",
    _ => "Unknown"
};
Console.WriteLine(priceCategory);

A Cheap

B Moderate

C Expensive

D Unknown

💡 Hint

Look at the Price property and see which range 19.99 fits.

The Price 19.99 is between 10 and 20 inclusive, so the output is 'Moderate'.