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

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested property pattern matching

What is the output of this C# code using property patterns?

C Sharp (C#)

record Address(string City, string Country);
record Person(string Name, Address Address);

var person = new Person("Alice", new Address("Paris", "France"));

string result = person is { Address: { City: "Paris" } } ? "Match" : "No match";
Console.WriteLine(result);

A Compilation error

B No match

C Match

D Runtime exception

💡 Hint

Check how nested property patterns match inner properties.

The pattern checks if the Address property has a City equal to "Paris". Since it does, the result is "Match".

❓ Predict Output

intermediate

Output of property pattern with discard

What will this C# code print?

C Sharp (C#)

record Product(string Name, decimal Price);

var product = new Product("Book", 12.99m);

string output = product is { Price: > 10, Name: _ } ? "Expensive" : "Cheap";
Console.WriteLine(output);

A Compilation error

B Runtime exception

C Cheap

D Expensive

💡 Hint

The discard (_) means any Name is accepted.

The pattern checks if Price is greater than 10 and ignores Name. Since Price is 12.99, it prints "Expensive".

❓ Predict Output

advanced

Output of property pattern with nested null property

What is the output of this code?

C Sharp (C#)

record Engine(int Horsepower);
record Car(string Model, Engine? Engine);

var car = new Car("Sedan", null);

string result = car is { Engine: { Horsepower: > 200 } } ? "Powerful" : "Not powerful";
Console.WriteLine(result);

A Not powerful

B Powerful

C NullReferenceException

D Compilation error

💡 Hint

Property patterns safely handle null nested properties.

The pattern checks if Engine is not null and Horsepower > 200. Since Engine is null, it does not match and prints "Not powerful".

❓ Predict Output

advanced

Output of property pattern with multiple conditions

What will this code print?

C Sharp (C#)

record Employee(string Name, int Age, string Department);

var emp = new Employee("John", 30, "HR");

string output = emp is { Age: (>= 18 and <= 65), Department: "HR" } ? "Eligible" : "Not eligible";
Console.WriteLine(output);

A Runtime exception

B Eligible

C Compilation error

D Not eligible

💡 Hint

Check the combined conditions with 'and' in property patterns.

The pattern matches employees aged between 18 and 65 in the HR department. John meets both conditions, so output is "Eligible".

❓ Predict Output

expert

Output of property pattern with positional and property patterns combined

What is the output of this code?

C Sharp (C#)

record Point(int X, int Y)
{
    public string Quadrant => (X, Y) switch
    {
        (> 0, > 0) => "First",
        (< 0, > 0) => "Second",
        (< 0, < 0) => "Third",
        (> 0, < 0) => "Fourth",
        _ => "Origin or axis"
    };
}

var p = new Point(5, -3);

string result = p is { X: > 0, Y: < 0 } ? p.Quadrant : "Unknown";
Console.WriteLine(result);

A Fourth

B First

C Unknown

D Compilation error

💡 Hint

Combine property patterns with positional pattern logic inside the property.

The pattern matches X > 0 and Y < 0, which is the fourth quadrant. The Quadrant property returns "Fourth".