예제

var p = new Person { Name = "Kim", Address = new Address() };

// C# 10 Extended Property Pattern
if (p is { Address.City: "Seoul" })
{
    Console.WriteLine("I live in Seoul");
}

class Person
{
    public string Name { get; set; }
    public Address Address { get; set; }
}

class Address
{
    public string Country { get; set; } = "Korea";
    public string City { get; set; } = "Seoul";
}