Linq操作数组

 class Program
    {
        static void Main(string[] args)
        {
            String[] arr = { "ACTIVE", "MAIN", "WANG", "TODAY", "TIME", "TARGET" };
            //查询字符串
            var queryStr = from str in arr
                        where str == "MAIN"
                        select str;
            Console.WriteLine(queryStr.ToList()[0]);
            //结果：MAIN

            //查询包含字符“M”的字符串的索引位置
            var query = from str in arr
                        where str.IndexOf("M") >= 0
                        select str.IndexOf("M");
            foreach (int item in query.ToArray())
            {
                Console.WriteLine(item);
            }
            //结果：0,2

          //获取查询的关键字符
            var q = from str in arr
                    where str.IndexOf("M") >= 0
                    select str;
            foreach (string item in q.ToArray())
            {
                Console.WriteLine(item);
            }
            //结果：MAIN  TIME


            Console.ReadLine();

        }
    }