using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace ConsoleApplication3
{
    //拡張メソッドを定義するクラスはstaticにさえしておけば、どんな名前にしてもいいよ！Class名は飾りだよ
    static class OresamanoTukuttaExtendMethods
    {
        public static bool In(this string input, params string[] others)
        {
            return others.AsEnumerable().Any(a => a == input);
        }
    }
 
    class Program
    {
        static void Main(string[] args)
        {
            string s1 = "TEST";
            string[] ss1 = new string[] {"aaa","bbb","ccc" };
            Console.WriteLine("{0}に等しい文字がss1配列にあるか？{1}", s1, s1.In(ss1));
 
            string[] ss2 = new string[] { "aaa", "TEST", "ccc" };
            Console.WriteLine("{0}に等しい文字がss2配列にあるか？{1}", s1, s1.In(ss2));
 
        }
    }
}
 

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