C# 21.04.05.복습

튜플

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Test
{
    class App
    {
        eGrade grade;
        enum eGrade { NORMAL, MAGIC, RARE, LEGENDARY, MYTHIC }
        public App()
        {
            Console.WriteLine("App 생성자 호출됨");

            (int id, string name) item = (1, "사탕");
            Console.WriteLine("{0} : {1}", item.id, item.name);

            Random rand = new Random();
            int index = rand.Next(0, 5);

            if (index == 0)         { this.grade = eGrade.NORMAL; }
            else if (index == 1)    { this.grade = eGrade.MAGIC; }
            else if (index == 2)    { this.grade = eGrade.RARE; }
            else if (index == 3)    { this.grade = eGrade.LEGENDARY; }
            else                    { this.grade = eGrade.MYTHIC; }

            (string name, eGrade gName) item2 = ("막대사탕", this.grade);
            Console.WriteLine("{0} // {1}", item2.name, item2.gName);
        }
    }
}

============================================================================

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Test
{
    class App
    {
        private int[,] arr;
        private int row;
        private int col;
        public App()
        {
            Console.WriteLine("App 생성자 호출됨");

            this.arr = new int[4, 3];

            this.row = arr.GetLength(0);
            this.col = arr.GetLength(1);

            this.arr[1, 2] = 100;

            Console.WriteLine("1차시 [1,2] = 100--------");
            this.PrintArray();


            arr[2, 0] = 200;
            Console.WriteLine("2차시 [2,0] = 200--------");
            this.PrintArray();

            Indexes indexesA = new Indexes(1, 2);
            Indexes indexesB = new Indexes(2, 0);

            this.Swap(indexesA, indexesB);

            Console.WriteLine("3차시 스왑 [1,2], [2,0]--------");
            this.PrintArray();

            this.Swap(new Indexes(0, 0), new Indexes(2, 0));

            Console.WriteLine("4차시 스왑[0,0], [2,0]--------");
            this.PrintArray();

        }

        private void Swap(Indexes a, Indexes b)
        {
            int temp = arr[b.rowIndex, b.colIndex];
            arr[b.rowIndex, b.colIndex] = arr[a.rowIndex, a.colIndex];
            arr[a.rowIndex, a.colIndex] = temp;
        }

        private void PrintArray()
        {
            for (int i = 0; i < this.row; i++)
            {
                for(int j = 0; j < this.col; j++)
                {
                    Console.Write("{0, 5}", arr[i, j]);
                }
                Console.WriteLine();
            }
        }
    }
}

============================================================================

오늘은 일찍 자야지 ㅎㅎ

 

++) 하나 더 했다.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Test
{
    class App
    {
        
        public App()
        {
            Console.WriteLine("App 생성자 호출됨");

            List<Book> books = new List<Book>();

            var book1 = new Book()
            {
                ID = "bk109",
                Title = "어린왕자",
                Genre = "Novel",
                PublishDate = new DateTime(2002, 01, 01)
            };

            var book2 = new Book()
            {
                ID = "bk108",
                Title = "콩쥐팥쥐",
                Genre = "Novel",
                PublishDate = new DateTime(2002, 01, 02)
            };

            Console.WriteLine(book1.ToString());

            books.Add(book1);
            books.Add(book2);

            /* List<Book> list = books.FindAll(FindComputer);

             foreach(Book book in list)
             {
                 Console.WriteLine(book.ToString());
             }*/

            List<Book> list = books.FindAll((book) =>
            {
                if (book.Genre == "Novel") return true;
                else return false;
            });

            Console.WriteLine(list.Count);

            foreach(var book in list)
            {
                Console.WriteLine(book.ToString());
            }

        }

        private bool FindComputer(Book book)
        {
            if (book.Genre == "Novel")
                return true;
            else
                return false;
        }

    }
}

List<Book> list = books.FindAll((book) => ~~~~

부분이 잘 안 와닿았는데 하다보니까 books 에서 FIndAll로 true를 반환한 값들이 하나의 리스트가 되어 list에 할당된 것 이라고 이해됐다.(맞겠지?)