C#(メソッド応用)

using System;
using System.Collections.Generic;

namespace MethodLesson
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            Console.WriteLine(ShowInfo());//ゴンベ(20)
            Console.WriteLine(ShowInfo("山田"));//山田(20)
            Console.WriteLine(ShowInfo("山田", 22));
            //名前付き引数
            Console.WriteLine(ShowInfo(age: 30));
            Console.WriteLine(ShowInfo(age:40, name:"田中"));

            //可変長引数
            Console.WriteLine(CalcAdd(2,3,5));
            Console.WriteLine(CalcAdd());
            Console.WriteLine(CalcAdd(2, 4, 4, 3));

            //Console.WriteLine(CalcAdd2()); 
            Console.WriteLine(CalcAdd2(2,3,4,5));
           
        }
        //引数の既定値
        public static string ShowInfo(string name = "ゴンベ", int age = 20)
        {
            return $"{name}({age})";
        }

        //可変長引数
        public static int CalcAdd(params int[] data){
            int sum = 0;
            foreach(var n in data){
                sum += n;
            }
            return sum;
        }
        //Calcメソッドは必ず１つ以上の引数を受け取るように改良
        public static int CalcAdd2(int first,params int[] data)
        {
            int sum = first;
            foreach (var n in data)
            {
                sum += n;
            }
            return sum;
        }

    }
}