41. 프로퍼티와 생성자

객체를 생성하고, 객체의 각 필드를 초기화하는 ... 또 다른 방법

바로 프로퍼티를 이용한 초기화

 

- 초기화하고 싶은 프로퍼티만 넣어서 초기화하면 된다.

 

 

이것을

using System;

namespace Property
{
    class BirthdayInfo
    {
        public string Name{ get; set; } = "Unknown";
        public DateTime Birthday { get; set; } = new DateTime(1,1,1);

        public int Age
        {
            get{ return new DateTime(DateTime.Now.Subtract(Birthday).Ticks).Year; }
        }
    }

    class MainApp
    {
        static void Main(string[] args)
        {
            BirthdayInfo birth = new BirthdayInfo();

            birth.Name = "서주현";
            birth.Birthday = new DateTime(1996, 04, 12);

            Console.WriteLine($"Name:{birth.Name}");
            Console.WriteLine($"Birthday:{birth.Birthday}");
            Console.WriteLine($"Birthday:{birth.Birthday.ToShortDateString()}");
            Console.WriteLine($"Age:{birth.Age}");
        }
    }
}

이렇게도 바꿀 수 있다.

using System;

namespace Property
{
    class BirthdayInfo
    {
        public string Name{ get; set; } = "Unknown";
        public DateTime Birthday { get; set; } = new DateTime(1,1,1);

        public int Age
        {
            get{ return new DateTime(DateTime.Now.Subtract(Birthday).Ticks).Year; }
        }
    }

    class MainApp
    {
        static void Main(string[] args)
        {
            BirthdayInfo birth = new BirthdayInfo()
            {
                Name = "서주현",
                Birthday = new DateTime(1996, 04, 12),
            };

            Console.WriteLine($"Name:{birth.Name}");
            Console.WriteLine($"Birthday:{birth.Birthday}");
            Console.WriteLine($"Birthday:{birth.Birthday.ToShortDateString()}");
            Console.WriteLine($"Age:{birth.Age}");
        }
    }
}

똑같은 출력 결과

Name:서주현
Birthday:1996-04-12 오전 12:00:00
Birthday:1996-04-12
Age:26

 

 

이것 나름대로 괜찮아보이긴 한다.

 

예제2

using System;

namespace InitOnly
{
    class Transaction
    {
        public string From{ get; set; }
        public string To { get; set; }
        public int Amount { get; set; }
        public override string ToString()
        {
            return $"{From,-10} -> {To,-10} : ${Amount}";
        }
    }

    class MainApp
    {
        static void Main(string[] args)
        {
            Transaction tr1 = new Transaction { From="Alice", To="Bob",Amount=100 };
            Transaction tr2 = new Transaction { From = "Bob", To = "Charlie", Amount = 50 };
            Transaction tr3 = new Transaction { From = "Charlie", To = "Alice", Amount = 50 };

            Console.WriteLine(tr1);
            Console.WriteLine(tr2);
            Console.WriteLine(tr3);
        }
    }
}

출력

Alice      -> Bob        : $100
Bob        -> Charlie    : $50
Charlie    -> Alice      : $50